Ruine Röthelstein occupies a striking 30-metre rocky outcrop on the Danube east of Hainburg an der Donau, directly facing Ruine Theben across the river in Slovakia. Built around 1160 and first documented in 1180, this fortress secured the Austrian Danube for centuries while its Slovak counterpart protected Hungarian and Slovak interests. The castle was dismantled in 1693-1694, with stones repurposed for Pressburg Castle expansion. A 2005 restoration project led by the Danube Auen National Park, Hainburg city, and Austrian heritage authorities exposed and stabilized the remaining wall sections, revealing this strategic medieval stronghold on the Danube.
