Terpen were usually well fertilized by the decay of the rubbish and personal waste deposited by their inhabitants over centuries. Wierden in the province of Groningen In the Dutch province of Groningen an artificial dwelling mound is called a wierde (plural wierden). As in Friesland, the first wierde was built around 500 BC or maybe earlier. List of artificial dwelling mounds Place names in the Frisian coastal region ending in -werd, -ward, -uert etc. refer to the fact that the village was built on an artificial dwelling mound (wierde). The greater part of the terp villages, though, have names ending in -um, from -heem or -hiem, meaning (farm)yard, grounds. There are a few village names in Friesland ending with -terp (e.g. Ureterp), referring not to a dwelling mound but merely to the Old Frisian word for village. The first element of the toponyms is quite often a person's name or is simply describing the environmental features of the settlement (e.g. Rasquert (prov. Groningen) Riazuurđ: wierde with reed, where reed grows). Some 1,200 terpen are recorded in Groningen and Friesland alone. They range from abandoned settlements to mounds with only one or a few farmhouses, to larger villages and old towns. A few of them are listed below. Friesland Aalsum () Bolsward (Boalsert) Britsum Cornwerd (Koarnwert) Dokkum Ee Ferwert Ginnum Hegebeintum Hitzum Jannum Jouswier Leeuwarden (Ljouwert) Metslawier Wijnaldum Groningen Adorp Bedum Bierum Ezinge Feerwerd Garnwerd Godlinze Holwierde Leens Middelstum Niehove Rottum Saaksum Spijk Stitswerd Ulrum Usquert Wirdum Northern Germany Loquard (East Frisia) Rysum (East Frisia) Eckwarden (Butjadingen) Itzwärden (Land Wursten) See also Platform mound Tell (archaeology) Crannog Literature Moritz Heyne (1899): Das deutsche Wohnungswesen. Von den ältesten geschichtlichen Zeiten bis zum 16. Jahrhundert, Bremen 2012. External links Warften/Wurten (page of the Society for Schleswig-Holstein History) Webseite zu den Warftendörfern Ziallerns und Rysum (private site) Historical site of Wüppel in the Wangerland Water supply in the North Frisian Marshland (private site) Manual making a Terp in 12 Steps (post of the Frisia Coast Trail) Vereniging voor terpenonderzoek (Foundation for terp research, the Netherlands) Indigenous architecture Coastal construction Artificial hills + Hills