The High Cathedral of Saint Peter in Trier is the oldest cathedral in the country.
The palace complex was supplanted in the 4th century by the largest Christian church complex from ancient times. It consisted of four basilicas joined by a large baptistry; the complex covered an area extending to the present Main Market. Tours under the building of the Cathedral Information show the remains of the first Early Christian assembly room north of the Alps from the late 3rd century and the remains of the first basilica.
Today’s Cathedral still contains a Roman central section with the original walls rising up to a height of 26 m (86 ft). The huge fragment of a granite column next to the entrance to the Cathedral is another indication of the Roman origin of the building. After destructions in the 5th and 9th centuries, the remaining nucleus was enlarged by Romanesque additions – today, the Cathedral, with its three crypts, its cloister, Cathedral Treasury, and Holy Robe Chapel, displays architecture and artwork from more than 1650 years.
The south part of the Roman double church was torn down around 1200 and completely replaced by the Early Gothic Church of Our Lady (Liebfrauen). Nothing above the surface is Roman any more, but there are extensive excavations (not open to the public) underneath the church and several of the Gothic pillars stand on top of Roman column foundations.
