Cologne’s history, and the fabric of the city today, is inextricably bound with the history of Rome. The museum was built around the magnificent Dionysius mosaic, produced in a Rhineland workshop in the 3rd century and discovered in 1941 by workers digging an air-raid shelter. Towering over the mosaic, which extols the joys of good living (something the Kölner are still good at), is the Tomb of Lucius Poblicius, constructed around a.d. 40 for a Roman officer; it is the largest antique tomb ever found north of the Alps.

The museum’s exhibits explore themes in the ldaily lives of the ancient Romans in Cologne: religious life, trade and industry, the cult of the dead, and so on. The museum covers the period that extends from the Stone Age to the period of Charlemagne (9th c.). On the second floor, you can see a superlative collection of Roman glassware and a world-renowned collection of Roman jewelry. On the lowest level, devoted to the daily life of the Romans, there’s an ancient black-and-white mosaic floor covered with swastikas. Centuries before the symbol became ominously identified with the atrocities of the Third Reich, the swastika—probably Indian in origin—was a symbol of good luck and happiness, and was known in Latin as the crux gamata. You need at least an hour to browse through the entire museum.