The halligen are the smallest and strangest of the North Frisian Islands — not true islands but low-lying tidal marshes that flood completely in storm surges, leaving only the farmhouses on their raised warften (artificial mounds) visible above the water. There are about ten halligen, most inhabited by a handful of families, and visiting them feels like stepping into a world where the relationship between land and sea has never been resolved.
Langeness and Hooge are the most accessible, reachable by ferry from Schlüttsiel. Hooge has a small guesthouses and a museum documenting the halligen way of life. The experience of being on a hallig at high tide, surrounded by water in all directions with only the warft above the surface, is completely unlike anything else in Germany. Visit between May and August for the best weather; winter storm surges are spectacular but access can be disrupted.