Kaltenburg Castle

Kaltenburg Castle stands as a ruined fortress above the Lone valley near Giengen and Niederstotzingen. Built in the 12th century by Heinrich von Kalden, it once served Emperor Frederick II as Reichshofmarschall. The castle’s owners included the von Helfenstein, von Riedheim and Stadion families over the centuries. It was besieged in 1435 by Nürnberg troops and again destroyed during the Thirty Years’ War. Rebuilding in 1677 added the two surviving square towers topped with pyramidal roofs.

The site shows four building phases from the original tower house to later expansions. A deep moat protected the curtain wall on the gentler hillside while the gatehouse stood near a steep cliff. The 1677 towers remain prominent across the valley, and fragments of the 13 m high keep and 3.4 m thick walls still mark earlier structures. Nearby Charlottenhöhle, one of the longest caves in the Swabian Alb, lies about 500 m north of the ruin.

Visitors find the irregular pentagon of curtain walls and the restored outer defences showing the castle as it looked in the 16th century. The two square towers built in 1677 rise above the plateau, offering views over the Lone and Hürbe rivers. Remains of the moat and sections of the east wall reveal how the fortress once stood. The rocky outcrop where the first tower house was built still supports part of the original masonry.