250 years ago, Birkesø was drained as part of a large-scale drainage project in Lille Vildmose. In 2017, the water returned and Birkesø once again became a lake.
With the return of water to the bog, the existing raised bog is prevented from drying out and breaking down. At the same time, good conditions are created for the raised bog to spread and, in the longer term, connect the current areas of raised bog.
Birkesø is shallow, with an average depth of 1 metre, and covers 130 hectares. Three low bird islands have been placed in the lake to create a breeding area protected from foxes. One of the bird islands lies directly opposite the viewing pavilion, from where visitors can enjoy the view across the lake without disturbing the birdlife.
A narrow-gauge railway runs from the visitor centre to Birkesø. There are several daily train trips to the lake.
