Without the 25km-long, 8m-high dike that surrounds it, this island would be inundated at each high tide. Sheep graze on the dikes, as much a part of the landscape as the Frisian cattle in the meadows. The island's main attraction is the ruined tower of the Alte Kirche St. Salvator (11-12C). Nearby is the Friedhof der Heimatlosen, the cemetery where the bodies of strangers washed ashore by the sea are buried. Here and there, vestiges of the villages engulfed by the tidal wave of 1634 can be seen.