Filsø, previously the largest lake in Jutland, but from 1852 and onwards most of the lake was reclaimed for cultivation. The remnants of the lake have, however, always attracted large flocks of resting water birds, and now about 914 ha lake surface has been recreated. Filsø was recreated in 2012 as part of one of the biggest natural restoration projects in the history of Denmark. There are more paths and bird observation towers to facilitate public access.

Filsø is now the 6. biggest lake in Denmark.