Trier Imperial Baths

The Trier Imperial Baths (Kaiserthermen) are a large Roman bath complex in Trier, Germany, constructed in the early 4th century AD during Constantine I's reign [1]. When built, Trier served as a major imperial hub and primary residence for Constantine's son Crispus [1]. The complex featured hot water pools reaching approximately 40°C (104°F) [1]. Beneath the baths, an extensive network of underground passageways allowed staff to move without disturbing bathers, and remnants of the sewer system survive today [1][2]. Despite their scale, the baths were never fully completed and were later converted into a medieval castle [1][2].