Roman City Gate St. Aposteln in Cologne

The Roman highway from Cologne to the Atlantic coast began at the central western gate of the Roman city wall. This structure consisted of a gatehouse with three passageways and two towers. Light-colored stones in the paving of the square in front of the eastern choir of St. Aposteln Church mark its former location. A bricked-up doorway at a height of 7.80 meters in the apse originally led to the wall-walk of the Roman city wall, which still stood here in the 12th century.

From the second half of the 1st century AD, a neatly laid-out suburb (suburbium) stretched in front of the Roman city wall along the Via Belgica. Beyond it lay burial grounds on both sides of the route, extending for about two kilometers.

In the Middle Ages, the Roman road between Neumarkt and Rudolfplatz ran across the farmland of the Aposteln monastery. Here, the road lost its function and was eventually abandoned. In 2008, the Via Belgica at this location was excavated during archaeological research. A preserved cross-section of the main road, along with adjacent paths and drainage ditches, can be seen in the foyer of the Fritz Thyssen Foundation in the former Amerikahaus (Apostelnkloster 13–15).

A church dedicated to the twelve apostles is first mentioned in written sources in 965. The basilica acquired its current form with a west tower and an apse featuring three semi-domes in the 12th century.