Kölner Häfen

A barge known as a Prahm, found beneath the Alter Markt and dating from around AD 43, is evidence of harbour activity at this spot. From about AD 50, the harbour lay between Groß St. Martin and today's Kurt-Hackenberg-Platz on a Rhine channel 60 to 70 metres wide. An island up to 180 metres wide and over a kilometre long separated it from the main stream. After the Romans extended the channel eastwards, the expanded harbour reached roughly from today's Breslauer Platz to the Holzmarkt, where the channel rejoined the main river. Around AD 150, the basin silted up after an extreme dry spell and was abandoned.

The Roman harbour gate is the only one of Cologne's nine Roman city gates that can be visited as architecture still standing in its original location. It was discovered during construction of the Nord-Süd-Stadtbahn, together with other remains dating from after AD 150. The gate was probably about 13.5 metres high and the city wall about 8 metres; a tower in the wall guarded the passage. For structural reasons, the gates along the harbour front did not project beyond the axis of the city wall. The 2.7-metre-wide, double-leaf wooden gate led to the quays and to the basalt-paved harbour road, which joined the Cardo maximus and is now laid out at the Römisch-Germanisches Museum. According to studies by the University of Cologne, more than 150 oak piles were all felled in the same year, AD 89 – so the city wall, harbour gate and drain outlet were built in the last decade of the 1st century AD.

According to Lampert of Hersfeld, in June 1074 Archbishop Anno II had a ship seized in Cologne's harbour so that his friend Frederick I could travel home. The owner successfully resisted, and angry citizens threatened the archbishop. Anno fled unnoticed through the recently built Annostollen and left the city in the direction of Neuss.