Aula Palatina

The Aula Palatina, also called Basilica of Constantine, at Trier, Germany, is a Roman palace basilica and an early Christian structure built between AD 300 and 310 during the reigns of Constantius Chlorus and Constantine the Great.Today it is used as the Church of the Redeemer and owned by a congregation within the Evangelical Church in the Rhineland. The basilica contains the largest extant hall from antiquity (see List of ancient Greek and Roman roofs. The hall has a length of 67 m, a width of 26.05 m and a height of 33 m. Because of its testimony to the imperial importance of Trier during the Roman Empire and its architecture, the Aula Palatina was designated as a UNESCO World Heritage Site in 1986 as part of the Roman Monuments, Cathedral of St. Peter and Church of Our Lady in Trier site.

Source: Wikipedia