Ubii Monument

The Ubii Monument is a square stone tower, now six meters high, that sits deep beneath a modern building at the intersection of An der Malzmühle and Mühlenbach. It remains the oldest securely dated structure from the Roman era in Cologne, built around the year four or five AD. The tower stands on a heavy foundation of greywacke and lime mortar, supported by a grid of oak piles driven into the gravel of the ancient Rhine flood plain.