Best ancient sites in Trier

Trier was an imperial residence of the late Roman Empire, and its three catalogue sites are part of the city’s UNESCO-listed Roman monuments. The Porta Nigra is the best-preserved Roman city gate north of the Alps, four storeys of darkened sandstone that you can climb inside. The Imperial Baths, begun shortly before AD 300 and never finished, keep high brick walls and service tunnels you can walk through. The amphitheatre, an earth-banked arena for about 20,000 spectators, is worth it for the cellar under its floor.