Neither islands nor mainland: the unique Halligen islands are located in the Wadden Sea Biosphere Reserve.
Hajo Bergmann
4.5
2005
7.5
2025
6.1
1929
0.0
6.3
1980
5.9
1979
7.2
2009
6.6
2021
4.8
2008
2017
6.5
2024
2023
7.1
1976
7.0
1973
2007