Castra of Lorch, Roman military fort in Lorch, Germany.

The Castra of Lorch is a Roman military fortress in southwestern Germany whose foundation walls remain clearly visible today. The site spans multiple areas with remains of barracks, storage buildings, and defensive earthworks that demonstrate its role as a strategic outpost.

The fort was built around 150/160 CE, after the unit previously stationed at Köngen on the Neckar was moved here; the garrison was a partly mounted unit whose name is not known. It was the last major military post of the province of Germania Superior, with the province of Raetia beginning a few kilometres to the east. The 2.47-hectare stone fort had rounded corners and walls up to 1.3 m thick faced with local Stubensandstein.

The site shows how Roman soldiers lived and worked here, with traces of their daily routines visible in the foundations. The remains give a sense of how coexistence between Roman occupiers and local people functioned on this frontier.

The site is accessible and can be visited in any season, with foundation walls remaining clearly visible. Sturdy footwear is helpful since the ground can be uneven and some areas are exposed.

The fort's dimensions are slightly skewed: the north side measures 158.4 m, the south 162.8 m, and the east and west sides 153.5 and 154 m. Researchers attribute this to surveying instrument error by Roman land surveyors. The corners of the rampart are rounded, giving the plan a playing-card shape.