The Kronenloch nature reserve, established in 1985, is fed by salt water from the North Sea, which enters a circulating channel via an inlet (Meldorfer Hafen) and is distributed around the island.
In the nature reserve, vegetation developed, from individual salt meadow plants to bushes with willow and sea buckthorn, largely without human influence. It is therefore forbidden to enter the immediate vicinity of the crown hole. But by building an observation platform and an observation hut, guests get an insight into the flora and fauna. Nature conservation information signs are available to give the observer precise, detailed information on how to observe the fauna and flora.
Bird species such as the barnacle goose, the wigeon, the curlew, the greylag goose, the redshank, the shelduck, the greenshank, the dunlin, the oystercatcher, the bluethroat and the reed warbler.
The NABU National Park House "Wattwurm" is on the other side of the street from the observation hut. In this house with its distinctive semicircular shape, which is based on a lugworm, extensive display boards and exhibits are available. Supervised by two volunteers, the NABU National Park House Wattwurm offers extensive information, a modern exhibition and a barrier-free nature trail. It is also the meeting point for various guided tours in front of and behind the dike.