The Knudshoved peninsula is formed from sand and gravel, eroded from the coast north of Nyborg and carried southwards with the current, where the material was deposited to form a peninsula. The Østerø Sø lake area is a Natura 2000 (a European nature conservation and projection project).
The lake and surrounding salt meadows are an importang breeding ground and forage territory for many ducks and wading birds. The waterholes in the salt meadows also provide habitats for amphibians such as the natterjack toad, the agile frog and the moor frog.
A nature path leads from the car park to the bird watching tower by Østerø Sø lake, so you can walk there without disturbing the birds. In the tower there are posters showing the birds you are most likely to see.