The Basilica of Constantine or Aula Palatina at Trier is a Roman palace basilica, that was built by emperor Constantine in the beginning of the 4th century AD.
Today it is a World Heritage Site and contains the largest single inner room, which remains from antiquity. The inner room has a length of 67 m, a width of 27 m and a height of 33 m.
The Aula Palatina was built around 310 AD as a part of the palace complex. Originally it was not a free standing building but had other smaller buildings attached to it, such as a forehall, an entrance vestibule and some service buildings. The Aula Palatina had a floor and wall heating system (hypocaust).