The Porta Nigra (Latin for black gate) is a large Roman city gate in Trier, Germany. It is the largest Roman city gate north of the Alps and has been designated a World Heritage Site.
The name Porta Nigra originated in the Middle Ages due to the darkened color of its stone; the original Roman name has not been preserved. The Porta Nigra was built in grey sandstone between 186 and 200 AD.
Cathedral of Saint Peter
Cathedral of Saint Peter is the oldest cathedral in Germany. Its dimensions, 112.5 by 41 m (369 by 134.5 ft), make it the largest church structure in Trier. Since 1986 it has been on the UNESCO list of World Heritage Sites.
The structure is raised upon the foundations of Roman buildings of Augusta Treverorum.
Imperial Bath (German: Kaiserthermen)
Public baths (thermae) built in Trier by Constantine. More than 100 metres (328 ft) wide by 200 metres (656 ft) long, and capable of serving several thousands at a time, the baths were built to rival those of Rome.
Text source: *Trier.* Wikipedia. 2011. Wikipedia Foundation. Inc. 22 Feb 2011.