Imperial Baths (Kaiserthermen)

The Imperial Baths were built in the 4th century as the prestige thermae of the imperial residence. They were never completed as a working bath, and later served as barracks and as part of the city wall fortification. Today they are a UNESCO World Heritage site, and the underground service corridors are fully accessible.

The original plan called for a full Roman bathing complex with the classical sequence of rooms used in antiquity: an apodyterium for changing, the heated caldarium for hot bathing, the lukewarm tepidarium, the cold frigidarium, and additional sweat rooms. Heating was provided by a hypocaust, the Roman underfloor and wall heating system, in which hot air circulated beneath floors raised on small pillars. What remains visible today are above all the massive apses of the caldarium and the extensive network of underground service and supply tunnels, which once carried fuel and water to the heating facilities.

After the end of Roman rule, the complex fell into ruin and was used for centuries as a quarry for buildings in Trier. The Kaiserthermen (Imperial Baths) only returned to public attention in the 19th century: the first documented excavations began in 1818, followed in the 20th century by extensive uncovering and restoration work. Today, guided tours along with multimedia and virtual presentations supplement the visit and help visitors understand the original function of each room.