Which closed-off freshwater lake is the largest lake in the Netherlands?

The IJsselmeer is the largest closed-off freshwater lake in the Netherlands.

It was created when the Dutch completed the Afsluitdijk in 1932, sealing off the former Zuiderzee from the North Sea. The barrier transformed a tidal saltwater inlet into a freshwater lake, as river water gradually flushed away the remaining salt.

The lake covers about 1,100 square kilometres but is remarkably shallow, with an average depth of roughly 4.5 metres. Its name comes from the IJssel River, which supplies most of its inflow. The lake is now important for freshwater storage, water management, transport and recreation.

A common mix-up is the Markermeer, which was separated from the IJsselmeer by the Houtribdijk in 1975. Although the Markermeer is also a major Dutch lake, it is a distinct body of water and is not the answer to this question.