Vilsegg Castle, Medieval castle ruins in Vils, Austria.

Vilsegg Castle is a ruin on a rocky hill about 60 metres above the Vils valley, near the Austrian-German border. Its main surviving structure is a six-storey bergfried, 17 metres high, with walls nearly two metres thick at the base. The tower measures 10.7 by 10.1 metres and has lost its east wall since the 1939 earthquake. The castle occupies a narrow plateau about 75 metres long and 15 metres wide.

The fortress was built around 1220 as a stronghold for the Hohenegg family serving the Bishopric of Kempten. After centuries of use, it was abandoned by the 18th century and fell into decay.

The ruins display features of Hohenstaufen architecture found in this Tyrolean region. The nearly square tower shape defines how the structure appears to visitors today.

Visitors can reach the ruins by hiking a steep path starting from the Chapel of St Anne up to the former outer gate. Sturdy footwear and sure footing are essential, especially when the ground is wet or muddy.

The bergfried's lower walls are nearly two metres thick, and its east wall has been missing since the 1939 earthquake, which also destroyed the elevated entrance. The tower was raised later and capped with a gable roof; brick appears in that upper section, while the rest is rubble stone with quoined corners.