Between Leffinge and Misthusum—Understanding the Basics of Terps

Hans Faber
Sep 29, 2024
21 min read

Updated: Aug 28

Man-made hills to dwell upon. Long thought of as typically Frisian, but they are anything but unique. Consider the Kincaid Mounds of the Mississippian people along the Cumberland and Mississippi rivers in the United States. Or the lomas (‘hills’) deep in Bolivia’s Beni district, raised above the Amazon’s seasonal floodwaters to provide ground for living and farming. Think too of the chinampas, the ingenious ‘floating gardens’ of the Aztec in Central America. And closer to our shores, the ancient crannogs of Scotland. Wherever people found themselves in watery landscapes without natural elevations—river floodplains, bayous, swamp forests, lakes, deltas, or tidal marshes—they built platforms to raise life above the floods, turning danger into fertile opportunity. No Einsteins or even lesser minds were needed to imagine it; this solution recurs again and again across human history. In this blog post, we trace the mounds you will encounter along the Frisia Coast Trail—from the southernmost terp of Leffinge-Oude Werf in Belgium to the northernmost terp of Misthusum in Denmark.

Definition & Varieties

A terp is an earthwork—a man-made raised mound built for the purpose of habitation. Its function was, and occasionally still is, to protect homes, livestock, and food supplies from flooding. A sanctuary amid a potentially perilous landscape. In some cases, these mounds were also used for growing crops—elevated acres serving a double purpose. Whether situated on tidal marshlands along the sea, on peatlands adjacent to those marshes, or beside rivers and estuaries, terps were uniquely suited to the environments of historic Frisia.

This wider Frisian region stretched along the southern coast of the North Sea, from the north-western part of the region of Flanders (Belgium) to the south-western tip of the region of Jutland (Denmark)—roughly 750 kilometers of coastal habitat. Terps ranged in scale: from small platforms supporting a single dwelling to larger mounds accommodating small settlements of a few hundred people.

Dobbe / dob / fehting / feeting / feith — These are other typical earthworks of the southern North Sea culture. On the salt marshes, you can still find man-made ponds used to collect rainwater, providing livestock with fresh water in an otherwise saline environment. These ponds—called dobbe, fehting, feeting, feith, etc.—could either be dug into a terp or formed by constructing a small circular dyke on the marsh itself to catch and store rainwater.

They resemble large grassy donuts, with the central hole filled with freshwater. In addition to supplying drinking water to sheep, cattle, and horses, these earthworks also served as refuges for animals during storm surges and floods.

To see many of these green donut-shaped structures, visit the extensive salt marshes of ’t Noarderleech in the province of Friesland, just north of the village of Hallum.

Since this is also a hiking blog, you can make a short circular hike on 't Noarderleech called Paardendobbenroute ('horses dobbes route') of 7 kilometers. Check the site of It Fryske Gea; the association for nature conservation in the province of Friesland. Know that the soil of this region is very suitable for breeding strong strong horses.

dobbes on the tidal marshland by Joost van Houdt

Hence, in addition to terps constructed on tidal marshlands—which we will refer to as 'saltwater terps'—the definition also includes the hundreds of terps found in the peatlands of the present-day province of Noord-Holland, particularly in the Waterland region. This category also encompasses the town-terps of settlements like Monnickendam and, indeed, Amsterdam. These terps, embedded in river and peatland landscapes, once numbered in the thousands across the Netherlands (Besteman et al 1992).

We will refer to this type, found in predominantly freshwater environments, as 'freshwater terps.' Although saltwater terps have won the global beauty contest—and they are the type that typically come to mind when we talk about terps—it is important to note that they are, in fact, only a subset of the broader terp tradition. Iconic, yes—but certainly not the whole story.

For an overview of the saltwater terps along the Wadden Sea coast of Germany and the Netherlands, check the website Wierden en Terpen. Check also our own trail map, which also indicates terp sites, including in the region of Flanders, the western coast of the Netherlands—that is, the provinces of Zeeland, Zuid Holland, and Noord Holland—and the southwest of the region of Jutland.

Freshwater terps in former peatlands were primarily house platforms. Over time, however, these terps have become invisible to the naked eye. The reason lies in the nature of peat: it behaves like water—it flows, just in slow motion. Over the centuries, these raised platforms gradually levelled out and merged with the surrounding landscape.

By contrast, saltwater terps built on tidal marshlands—constructed from clay, often mixed with cow dung and shells—remain visible for much longer. That said, clay too is not immune to time; it also flows, albeit in super slow motion.

In addition to freshwater terps on peat soils, there are also several hundred freshwater terps in the river region of the Central Netherlands, particularly in the area known as Batavia—or Betuwe in the Dutch language. This landscape remained unembanked until around the year 1000, when dykes (also spelled dikes or called levees) were first constructed.

Dutch place names and toponyms such as pol, heuvel, hof, werf, and woerd may refer to these former earthworks—either used for dwelling or as refuges during river floods. The toponym woerd, in particular, may also indicate an elevated acre of land. Of all the identified terps in this region, roughly 580 are classified as dwelling mounds, the majority of which are located along riverbanks and constructed from clay and sods (Eijgenraam et al 2022).

terp Wetsens in the province of Friesland by vituswetsens.nl

To complicate matters further, the distinction between freshwater and saltwater was often fluid in practice. Even after high-dyke construction began toward the end of the first millennium—effectively cutting off the sea from the land—it still made sense to build raised platforms for farmsteads, particularly in low-lying areas. During the wet seasons, excess rain and river water could not yet be efficiently drained into the sea, causing basin levels to rise and leading to widespread flooding by freshwater (Blumenberg 2002).

This seasonal inundation, which could last for months, was famously described by Mary Mapes Dodge as “contrary land” in her 1865 novel Hans Brinker, or The Silver Skates. A similar scene is vividly portrayed by Hylke Speerstra in his novel De Oerpolder (2006), set in the nineteenth-century polder known as It Heidenskip—an isolated waterland in the southwest of Friesland. From that book, the following passage:

“Herfst 1824. ‘De regen gestadig aanhoudende en de bijkomende harde winden in November en December maakten dat alles spoedig onder water geraakte zoo dat de meeste boeren hunne polders geheel onder water hadden. Men vreesde al gestadig voor onze Vriesche Zeedijken, dog dij hielden het uit”

“Autumn 1824. ‘The steady persistent rain and the additional strong winds in November and December made that everything became inundated so that most of the farmers had their polders covered with water. People increasingly feared for our Frisian Sea-dykes, however, these endured” (The Diaries of Lieuwe Janszoon de Jong)

So, water coming at you from all sides—sideways and from above. Sea, river, and sky. Fresh or salty. Frozen or flowing. Either you are a true North Sea delta, dealing with all this nonstop, or you are just pretending to be one.

Terps on Kampereiland ('Kampen Island,' with kampen or campen meaning 'enclosed or confined land') in the delta of the River IJssel near the town of Kampen belong to this fluid category—situated in a brackish landscape. This changed only after the Zuiderzee ('southern sea') was sealed off in the 1930s by the construction of the 30-kilometer-long Afsluitdijk ('enclosure dyke'), transforming the Zuiderzee gradually into a vast freshwater lake now known as the IJsselmeer or Lake IJssel.

Kampereiland’s fertile soil is a rich blend of sea and river clay. In 1364, the town of Kampen was granted rights over fourteen islands in the river delta, which later formed Kampereiland. The earliest recorded mention of terps on Kampereiland dates back to the fifteenth century, coinciding with when the islands first became inhabited (Nijlunsing 2016, Molema 2018).

On Kampereiland, a terp is locally called a belt or huisbelt ('heap or house heap'), or sometimes a pol ('clump'). These mounds typically rise about 2 to 3 meters above mean sea level. The oldest terps in this delta are found along the riverbanks (Eilander & Heijink 1990).

There are roughly a hundred farmyards on Kampereiland, most of which are built atop a huisbelt (Molema 2018). You can find many of them along Frieseweg ('Frisian Road'). Do not miss the local history museum Ons Erf 29, where a farmstead preserved in its original state—including barns and haystacks—is open for visitors.

huisbelt or terp Kampereiland — bult ‘terp’ on Kampereiland, the province of Overijssel by Hans Faber

Saltwater terps—as said, the iconic subset of terps—occur in relatively large numbers, particularly along the Wadden Sea coastlines of Denmark, Germany, and the Netherlands. They can also be found along the northwest coast of Flanders in Belgium, where this area, together with the province of Zeeland in the southwest of the Netherlands, once formed a tidal landscape very similar to that of the Wadden Sea.

The oldest saltwater terps are found in the former territory of Westergo in the province of Friesland, dating back to around 600 BC. From there, the practice of building terps spread eastward along the coast into northern Germany. Today, all former tidal marshlands along the Wadden Sea are dotted with these manmade mounds. Moving from west to east, these areas include the marshlands of Friesland (Netherlands), Groningen, Ostfriesland, Friesland (Germany), Jeverland, Butjadingen and Stadland, Land Wursten, Land Hadeln, the Wesermarsch, Dithmarschen, Nordfriesland, and finally Jutland.

The northernmost saltwater terp is located at the former hamlet of Misthusum in southwestern Jutland, southern Denmark—just across from the Wadden Sea island of Rømø. Unfortunately, it was abandoned in 1814 when its last inhabitant left for good: the end of history. At the southern end of the North Sea coast lies the terp Oude Werf, just east of the village of Leffinge in western Flanders, Belgium (more on this below). Hence, the title of this blog post: 'Between Leffinge and Misthusum.'

Because people lived on terps in tidal marshlands—and high dykes had not yet been constructed—the sea was free to spread across vast stretches of land during spring tides and storm surges. Saltwater terps were, on average, no higher than +4 meters above mean ordinary discharge (MOD), comparable to those on Kampereiland. There was no need to build higher: it simply was not worth the effort. Hauling wet clay is hard, time-consuming work. And crucially, the landscape could absorb the sea’s movements. During high tides or storms, the water would spill over the marshes and then recede again, usually without causing significant harm to houses, people, crops, or livestock—thanks to the sheer capacity of the open land to store water. The landscape could breathe, so to speak. On average, the sea would submerge the land around fifty times a year.

An iconic terp (or what's left of it) that deserves the spotlight is the one at the hamlet of Hogebeintum in the province of Friesland. It is the tallest terp of them all, rising to nearly +9 meters above MOD. Why the villagers of Hogebeintum went to such ambitious heights in the Early Middle Ages—when +4 MOD would have done the job just fine—remains a mystery. Was it an early form of social flexing? “Check out our terp, peasants.” The medieval equivalent of a Porsche Panamera, perhaps? Or were there deeper, more spiritual motives—some kind of Babylonian reach-for-the-heavens logic? Maybe the locals were just deeply shaken by a devastating flood and decided to overcompensate, with no early-medieval therapist around to help process the trauma. Or, more simply, maybe they just had too much time on their hands. We are stumped—and genuinely open to better theories.

Other well-known saltwater terps include those of Fallward and Feddersen in Landkreis Cuxhaven, as well as the terp of Ezinge in the province of Groningen. The latter is often dubbed the 'Pompeii of the North'—a nickname earned thanks to the extraordinary archaeological excavations carried out before the Second World War (Nieuwhof 2020). These large-scale digs revealed remarkably well-preserved structures and artifacts, offering invaluable insights into the daily lives, economy, and culture of the marshland communities from the Iron Age through to the Early Middle Ages.

Former saltwater terps can also be found beyond the present-day Wadden Sea coast. One notable example is the region of Westfriesland in the province of Noord Holland, further to the south. Here, two terp clusters have been identified, each comprising roughly thirty mounds (Borger 2021). One cluster lies in and around the town of Schagen, including the terps of Avendorp and Hemkewerf. The second cluster is situated near the villages of Eenigenburg and Warmenhuizen. Although no longer coastal, these terps can still be considered part of the broader Wadden Sea terp tradition, as the coastline once extended this far south—before major land reclamation projects in northern Noord Holland reshaped the landscape in the decades leading up to the Second World War.

Underneath the marine town of Den Helder in the upper north of the province of Noord Holland also lay an old saltwater terp. It was named 't Torp meaning ‘the village’. Actually, it was the terp of the former medieval settlement of Edesthorpa. Located near natural park and museum De Nollen, where once a small island was, and near the current neighbourhood De Schooten. According to an early-medieval charter settlement Edesthopra had three feudal farmsteads. The name Edesthorpa possibly means 'village' at watercourse' (Minneboo 2017). Sadly, terp 't Torp was excavated in the '60s of the twentieth century (Van Berkel 2017). A fate it shares with so many other terps, as we will see further below.

Terps can also be found on the (former) islands of Marken, Schokland, and Urk in the area of the former Zuiderzee. These islands were, in fact, Hallig-like islands—similar to those still found today in the Nordfriesland region of Germany (see further below). They are clay islands resting on peat soil, remnants of old tidal marshlands.

On the island of Marken, fifteen of the original twenty-seven terps—locally called werven—still remain. Notable examples include Wittewerf, Kerkbuurt, Remmitswerf, Kets, Moeniswerf, Grotewerf, Altena, and Rozewerf. Some werven have been lost to the sea, such as Kraaienwerf, Thamiswerf, and Houtemanswerf, three terps that disappeared between 1720 and 1775 (Aarsen et al 2000, Rijkswaterstaat 2024). Although Marken is now connected to the Noord Holland mainland by the two-kilometer-long Zeedijk road, it can still be considered a Hallig island—only now it is surrounded by a lake instead of the sea.

The former island of Schokland consisted of three terps: Emmeloord, Middelbuurt, and Zuidert. Today, both Schokland and Urk are part of the embanked Noordoostpolder and belong to the province of Flevoland.

Further south, in the province of Zuid Holland, more terps can be found on the island of Hoeksche Waard, particularly near the village of Strijen. On this island, a terp is locally known as a hil or hille. Compare, for instance, the village name Piershil (Bank & Bosscher 2021). At the village of Maasdam, archaeological remains of a hille have also been discovered. The historical landscape of Hoeksche Waard closely resembles that of Kampereiland—only here, the terps are called (huis)belten.

Interestingly, the word hil is not unique to Hoeksche Waard. It also appears on the former island of Walcheren in the province of Zeeland, in the name of the dune Hoge Hil. Naturally, the Dutch hille and the English hill share the same linguistic root. Given that the (former) islands of Hoeksche Waard and Walcheren lie just across the Southern Bight from England, this shared heritage is hardly surprising.

island Hoeksche Waard — west of the island of Hoeksche Waard with several hillen ‘terps’ depicted on it, ca 1530 by Jan de Pape

Even further to the south, in the region of Flanders, one can find former saltwater terps at the villages of Leffinge, Bredene, and Oude Werf near Leffinge. As mentioned, Leffinge-Oude Werf, meaning 'old terp', is the southernmost terp of the North Sea coast as well. Other terps in the Zwin area in the region of Flanders are suspected to be at Knokke, Koudekerke, Oostkerke, Ramskapelle, and Westkapelle. Additionally, the toponyms Lockwierde, Houtwerf, Outvaarts Werf, Bogaerts Werf, Zuidwerf, Stekels Werf, Boenzacs Werf, Blevins Werf, Barezeles Werf, Molenwerf, Monnikewerve, Wallewerve, Weerdenwal, and many more might all refer to the (former) presence of earthworks. Much archaeological research still needs to be done in the region of western Flanders, including in the Zwin area. Check also our blog post A Frontier known as Watery Mess: the Coast of Flanders to find more information about the early-medieval Flemish-Frisian terp habitation in this region.

The last of the Mohicans

Although most saltwater terps have lost their protective function after land had been secured by big-dyke building from around the start of the second millennium, there’s one big exception, namely those in Landkreis Nordfriesland. Here, one can still witness people living on terps within the full dynamics of the sea, unprotected by high dykes. These are the so-called Hallig-islands mentioned earlier, which are saltmarsh islands with one or a few terps on them. The soil they are built on is clay on peat, a fragile composition once peat gets exposed to the grasp of the sea. Hallig-terps, sometimes supporting only one farm or house, sometimes supporting a tiny village. For more information about the Hallig-islands, read also our blog post How a town drowned overnight. The case of Rungholt.

terp Hallig Hooge in Nordfriesland — Warft on Hallig Hooge Nordfriesland by hooge.de

Recently (2021), after a thousand years, the terps on the Hallig-islands of Nordfriesland have been raised once again. To brace themselves for climate change, global warming, and rising sea levels. Moreover, the islanders are trying to stimulate the sedimentation of clay with low dykes and breakwaters of stone, attempting to let the Hallig-islands rise parallel to the rise of the sea. As they say in Nordfriesland: "Mit jedem Sturm wächst die Insel" ('with every storm the island grows').

We love the terp names on the Hallig-islands. To name most of them: Bandixwarf, Hanswarft, Honkenswarf, Ipkenswarft, Knudtswarft, Lorenzwarft, Mayenswarf, Ockelützwarft, Ockenswarft, Tammwarft, and Volkertswarft. Not too different from terp names on the island of Marken mentioned earlier.

Note that when you are in Nordfriesland, be mindful when talking about Halligs. Saying to a North Frisian that a Hallig is an island is inconsiderate. He or she will correct you in a grumpy voice and say it is not an island. Then he or she will probably say “moin” to you and walk or swim, depending on the tide, away. They are right in that Hallig-islands used to be part of a vast saltmarsh area, which largely was lost to the sea in the course of the High Middle Ages. Too fresh in the memory in the psyche of the Nordfriesen to be forgotten, if ever. Admitting it is an island would be admitting your defeat against your eternal enemy and benefactor, which took so much fertile land, livestock, and especially so many lives in the past.

A former Hallig is that of Dagebüll, today a municipality of the mainland of the region of Nordfriesland. You can find quite many terps here, like Bahnenswarft, Borderswarft, Gabrielswarft, Nordwarft, and Tudenswarft.

Terps, a current solution

In 1930, when the Wieringermeer Polder was created in the northeast of the province of Noord Holland, a huge terp was also made, four hectares big, next to the newly founded village of Wieringerwerf. It even became of service in 1945 when the dyke surrounding the polder was destroyed, and the polder became inundated. Go to our blog post Refuge on a terp 2.0. Waiting to be liberated for more about what happened there and at the end of the war.

In 2015, another eight brand new terps were erected, each 6 meters high. This time, freshwater terps in the Central Netherlands in the Overdiepse Polder of the province of Noord Brabant (Quekel 2015). The terpenplan (‘mound plan’), as it was called, was a private initiative of local farmers and became part of the plans of the national government to give the River Meuse a broader riverbed again to prevent dyke breaches and subsequent flooding. This followed the critical situations in the years 1993 and 1995.

Recently (2019), the federation Broek Polder reconstructed the so-called Rottahuis (‘Rotta house’), viz. the River Rotta, with a platform dating to the year 1015 in the town of Vlaardingen in the province of Zuid Holland, then still called West Frisia. It illustrates how the Frisians lived in the river delta of the River Meuse. Go visit it, now part of the interesting experimental archaeological site Masamuda.

So, we are happy to see that terp building is a 2600-years-old tradition still alive along the southern North Sea coast. But to the take the safety instructions and warnings very serious when building a terp. Therefore use our DIY manual—Making a Terp in only 12 Steps.

Statistics & Money

When talking about numbers, the estimation is that about 500 terps existed on the (former) tidal marshlands of the province of Friesland (Besteman et al 1992). House platforms have been left outside this number. Numbers vary too. During a stocktake in 1905, including house platforms, the number of terps amounted to 574 in the province of Friesland, and in 1944 the number amounted to 910. The most recent (2020) numbers are that in the province of Friesland 955 terps have been identified of which 679 have been partially or completely leveled, and in the province of Groningen 587 of which 268 have been partially or completely leveled. However, still new terps are being discovered in the landscape. The total original number of saltwater terps in the north of the Netherlands, both terps proper and house platforms, is estimated to be almost 2,500 (Nieuwhof 2020). So, just wait and over time the number of terps will rise.

If we want to be more precise, we should talk about ‘terp remains’ instead of terps since nearly all terps have been commercially exploited, excavated and levelled. The terps one can still see in the provinces of Friesland and Groningen, are mostly the remains of once much more impressive terps, or those which are fully covered with houses, farmsteads and a church, and thanks to this escaped commercial quarrying.

terp Ried — quarrying of the terp of Ried in the province of Friesland in 1906

Around the year 1900, terps in the northern Netherlands — and to a lesser extent in the region of Ostfriesland in Germany—were extensively excavated for commercial purposes. The rich, dark terp soil, the terra preta of the Low Countries, was highly prized as fertilizer for poorer soils, such as the sandy grounds of Drenthe province. In 1890, terp soil sold for 70 cents (guilders) per tonne—a considerable sum at the time—and by 1920 the price had risen to 110 cents per tonne.

Commercial quarrying of terp soil ceased in the 1940s, not due to the outbreak of the Second World War, but simply because so few terps remained economically viable for excavation.

While these large-scale digs led to the discovery of many valuable historic artifacts, there was a downside: much archaeological context was lost, especially the provenance of finds, and countless small objects were scattered far and wide as the terp soil was spread as fertilizer across the country. Wooden artifacts that went unnoticed probably did not survive this reckless treatment as fertilizer.

What is in the Name

Notice that we used the word terp as used in the province of Friesland—and recently in the province of Noord Brabant, too. People in the province of Noord Holland, however, mostly use the word werf. In the province of Zeeland and the region of Flanders the word werve is being used, although the toponym wi(e)rde or weerde and stelle also exist. The word werve in the province of Zeeland mainly because people there prefer to put the letter e behind every single word they pronounce. In the province of Groningen the word wierde is always being used. Official German is Wurt but the Nordfriesen use mainly warf and warft. The Rüstringer Friesen in the Lower River Weser area use Warden as most of the villages have this as a suffix. Frisere (‘Frisians’) in the very southwest of the region of Jutland use the words værft or varft.

The Old Frisian word hwarf and the current word werf, and all the variants aforementioned, indicate a mound or a landing. Werf and warft would, therefore, be more appropriate terms for a dwelling mound than the internationally adopted word terp. Do not tell this to the Frisians in the province of Friesland! The word terp derives from þurpa in the proto-Germanic language, meaning house or farmstead (Kuipers, Jensma & Vries 2011) and is related to torp (Danish language), doarp (Mid Frisian language) or dorp (Dutch language) which means village. It is terp and not warft, wierde, etc. that found its way into the English and Flemish languages. Therefore, we settle the discussion this way. Majority always rules.

The names, often suffixes, for artificial dwelling mounds we have found: aard, (huis)belt, hille, pol, stelle, terp, tarp, uard, uert, varft, værft, vliedberg, warf, warft, ward, weer, wehr, werd, werf, werve, wier, wierde, wird, woerd, wörd, wöhrd, woort, wort, worth, würd, würde, wurt, and wurth. For an overview, check the atlas ‘De Bosatlas van de Wadden‘ (2018). The word vliedberg can either donate a mound for cattle the flee to during floods, a remnant of motte-and-bailey castle, or a terp proper. Taking this whole history into account, the newly founded town of Wieringerwerf is a combination of wier and werf, in other words a tautology. To blend everything even more, the town of Wieringerwerf also has a street name called Terpstraat ('terp street'). Wier, werf, and terp—de Nederlandse poldermentaliteit or the Dutch consensus model: something in it for everyone. Not for nothing it is a village in the polder.

Note 1 — Ever planning to erect a terp yourself, find here our DIY manual—Making a Terp in only 12 Steps.

Note 2 — In the lead of this blog post, we made a comparison with the Native American cultures. Earlier, we found another striking parallel concerning the use of land, namely the terra preta ('black soil'). This is particularly evident between the Drenth Plateau and the Amazon. The technique of the terra preta dates back to 1000 BC and is about how to fertilize the soil. Be in awe reading our blog post The Killing Fields—of the Celts.

Note 3 — There are a few initiatives underway to recreate terps. One has already been realized: Terp fan de Takomst near the village of Blije. However, this is not a true terp in the traditional sense, but rather an artwork that pays tribute to terp history. Beautiful initiative, by the way. Another initiative, Magna Frisia, aims to build a terp on the tidal marshlands of Friesland, recreating it as it might have looked in the Early Middle Ages (RondOm Vandaag 2024). At the heart of this concept is a grand Viking-style hall — an impressive piece of architecture. That said, there is no archaeological evidence that such monumental halls ever stood in Frisia during that period. But hey, imagination has its charms.

What we do not quite understand is why the most obvious option is being overlooked: restoring existing terp remnants—such as those at Ezinge and Hogebeintum—to their former glory. How magnificent would it be to see some of these iconic terps rebuilt with earth, reshaped into their original form, and rising once more in their native landscape? It must be a (more) stunning sight to behold!