Tinnumburg, Sylt

The Tinnumburg is a departed ring wall complex near the district of Tinnum in the municipality of Sylt in Schleswig-Holstein.

While Archsum Castle has been destroyed and Rantum Castle is buried under dunes, it is the best preserved of Sylt's three castles. In the northwest it is bordered by a Prielstrom flowing into the Wadden Sea, in the southeast by the flat marsh. Possibly the Prielstrom and the Döplem, a lake situated next to the castle, were navigable in the Viking Age, so that the castle had access to the sea. To the east, the castle was connected to the Geest by a land bridge.

The castle was built around the birth of Christ. The ring wall has a diameter of 120 meters. The rampart is up to seven meters high and has a circumference of about 440 meters. The base of the castle is about two meters above sea level. Before the diking of the marsh in 1938, the castle rose out of the water like an island during storm surges. The castle had at least two gates. Perhaps it had a third gate in the west, which led to a small plateau located on the Döplem.

Excavations in 1870, 1948 and 1976 provided evidence that the Tinnumburg was one of the circular ramparts built on the North Frisian Islands in the early Roman imperial period. The excavation results revealed that it was a Germanic cult site. It was used again in the 8th to 10th centuries, after lying fallow for a while and becoming boggy. The interior construction consisted of sod wall houses. The rampart that is visible today also dates from this period. It was built over the rampart from around the time of Christ's birth.

The equally old Lembecksburg on Föhr brought comparative finds to the Tinnumburg.