Jaromarsburg was the religious centre of the Rani, a West Slavic tribe that controlled Rügen and large parts of the southern Baltic coast through the early Middle Ages. The temple here, dedicated to the four-headed god Svantevit, was the most important pagan shrine in the western Slavic world. The fort fell to a Danish crusade in 1168, and with it, the last organised pagan worship on the Baltic.
What survives today is the line of earthen ramparts curving around the headland above the chalk cliffs at Cape Arkona — most of the original interior has fallen into the sea over the past 800 years, and the coastal erosion continues at a metre or so per decade. A short interpretive trail along the ramparts explains what is left.
The site is a few minutes' walk from the Cape Arkona lighthouses.