Helfenstein Castle, Medieval castle ruins in Geislingen an der Steige, Germany.

Helfenstein Castle is a hilltop fortress overlooking Geislingen an der Steige, where stone walls and structures from its medieval past still stand. The ruins sit prominently on the elevated ground, allowing views across the surrounding landscape below.

The fortress was built around 1100 and served as the family seat of the Counts of Helfenstein for several generations. It was destroyed in 1552 during regional conflicts and never rebuilt.

The castle was the ancestral seat of the Counts of Helfenstein, who by the mid-14th century held a largely contiguous territory around Geislingen, Heidenheim, Blaubeuren and Wiesensteig. A stone relief with the Helfenstein coat of arms and a memorial plaque in the wall of a former gatehouse commemorate Count Ulrich V's marriage to Duchess Marija Kotromanić of Bosnia, who lived at the castle from 1356 to 1396. From 1983 to 2012 the ruins hosted the annual Helfenstein Festival, a rock and punk music event.

The ruins are reached by hiking trails marked clearly from Geislingen an der Steige town center going uphill. The walk takes about an hour and the paths are visible throughout, though some sections become steeper.

A Christmas 2022 wall collapse led to a survey that found early 11th-century pottery, suggesting the site was occupied before the castle was built. The castle was also the childhood home of Duchess Marija Kotromanić of Bosnia, who lived there from 1356 to 1396 after marrying Count Ulrich V of Helfenstein.