Aula Palatina (Basilica of Constantine), Trier (must see)

The Basilica of Constantine is a Roman palace basilica that was originally built between AD 300 and AD 310. It currently houses the Church of Our Redeemer and is part of Trier's UNESCO World Heritage Site.

The Basilica of Constantine was originally part of a complex, not the stand-alone building it is today. The basilica was constructed in solid brick with black and white marble floors and an impressive floor and wall heating system.

The Bishop of Trier used the building as his residence during the Middle Ages. The basilica was incorporated into the archbishop Lothar von Metternich's palace during the 17th century. During the 19th century, Frederick William IV of Prussia restored the building to its Roman state.

The Basilica became a Protestant Church in 1856. It was rebuilt after being damaged during World War II. Restorers didn't replace the inner decorations, so visitors can see the brick walls from the inside.

The Basilica of Constantine is an impressively large building at 33 meters high (108 feet) and 67 meters long (220 feet). The basilica's windows create an optical illusion that makes the building look even bigger than it is.

Excavation work underneath the basilica has been preserved, and visitors can take a guided tour to view the underground Roman area. The basilica also hosts several inspirational concerts every year.