The Westfriese Omringdijk (West-Frisian Circular Dyke) is a dyke system that protected the region of Westflinge, part of the historical region of West-Frisia. Westflinge is now commonly referred to as West-Frisia as the rest of historical West-Frisia assimilated with

The Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

. The cultivation of peat bogs and moors as of 1000 BC led to

subsidence Subsidence is a general term for downward vertical movement of the Earth's surface, which can be caused by both natural processes and human activities. Subsidence involves little or no horizontal movement, which distinguishes it from slope mov ...

, which necessitated the building of dykes. The Westfriese Omringdijk was formed by connecting a large number of smaller dykes. This was completed by 1250 AD, just in time for the area to be spared annihilation in the

St. Lucia's flood North Holland, 1st-10th century St. Lucia's flood (Sint-Luciavloed) was a storm tide that affected the Netherlands and Northern Germany on 13/14 December 1287 ( OS), St. Lucia Day and the day after, killing approximately 50,000 to 80,000 peo ...

of 1287. The total dyke length is about 126 km, protecting an area of about 800 km². It connects the cities of Enkhuizen,

Hoorn Hoorn () is a city and municipality in the northwest of the Netherlands, in the province of North Holland. It is the largest town and the traditional capital of the region of West Friesland. Hoorn is located on the Markermeer, 20 kilometers ...

Alkmaar Alkmaar () is a city and municipality in the Netherlands, located in the province of North Holland, about 30 km north of Amsterdam. Alkmaar is well known for its traditional cheese market. For tourists, it is a popular cultural destination. The ...

Schagen Schagen () is a city and municipality in the northwestern Netherlands. It is located between Alkmaar and Den Helder, in the region of West Friesland and the province of North Holland. It received city rights in 1415. In 2013, Schagen merged wit ...

Medemblik Medemblik () is a municipality and a town in the Netherlands, in the province of North Holland and the region of West-Frisia. It lies immediately south of the polder and former municipality of Wieringermeer. History Medemblik was a prosperous ...

and then back to Enkhuizen.

Sources

Westfriese OmringDaik Sait
*http://watercanon.nederlandleeftmetwater.nl/view/canon/dykeconstruction {{coord missing, Netherlands Coastal construction West Frisia Dikes in the Netherlands 13th-century establishments in Europe