The High Cathedral of Saint Peter in Trier is a Roman Catholic church in Trier, Rhineland-Palatinate, Germany. It is the oldest cathedral in the country. The edifice is notable for its extremely long life span under multiple different eras each contributing some elements to its design, including the center of the main chapel being made of Roman brick laid under the direction of Saint Helen, resulting in a cathedral added onto gradually rather than rebuilt in different eras. Its dimensions, 112.5 m length by 41 m width, make it the largest church structure in Trier. In 1986 it was listed as part of the Roman Monuments, Cathedral of St. Peter and Church of Our Lady in Trier UNESCO World Heritage Site.