Hohentwiel fortress ruins rise above volcanic cones in Germany

The Hohentwiel fortress, located on a volcanic cone in the Hegau region of Baden-Württemberg, Germany, stands as the largest ruined fortress in the country. Spanning 9.3 hectares, the site has a history dating back to 915. Originally a medieval castle, it evolved into a territorial fortress for Württemberg during the 17th century.

Visitors can explore the complex via paths that lead past ancient service buildings, wine cellars, a bakery, and a forge. The site features a historical bell tower with a panoramic platform that offers views of the Hegau volcanic cones, Lake Constance, and the Alps on clear days. Hohentwiel is one of several medieval fortifications in the area built upon volcanic peaks, alongside sites such as Hohenkrähen, Mägdeberg, and Staufen.