Kornwerderzand is located approximately 4 kilometers from the coast of Friesland, on a former artificial island which was created during the construction of the dam. The settlement has a population of 22 (as of January 1, 2007). It is part of the municipality of Wonseradeel.

The shipping locks at Kornwerderzand, also known as the Lorentzsluizen (“Lorentz Locks”), provide access to the Wadden Sea from the IJsselmeer, and a complex of discharge sluices control the water level in the IJsselmeer.

A second complex of sluices and locks is located at the other side of the Afsluitdijk, near Den Oever. Afsluitdijk The Afsluitdijk provides a road link between the provinces of Friesland and North Holland. Since North Holland was part of Vesting Holland (“Fortress Holland”), the national redoubt of the Netherlands at the time, and control of the sluices in the Afsluitdijk was necessary for planned defensive inundations in case of a military invasion, Kornwerderzand was considered strategically important by the Dutch government.

From 1931 onwards, fortifications consisting of seventeen casemates and three bunkers were constructed. The position was manned with approximately 220 troops in 1939.