Romano-Germanic Museum

Stand on the wide stone square beside Cologne Cathedral and listen for a moment. Pigeons scatter across the paving. A street musician tunes up somewhere near the steps. Tram bells ring from the station behind you. Now turn away from the great Gothic towers and look at the low, flat building on the south side of the square. It is easy to walk past. But behind its broad glass windows lies one of the oldest stories this city has to tell.

This is the Romano-Germanic Museum. It holds the archaeology of Cologne, from the Stone Age through the Roman centuries and into the early Middle Ages. Most of all, it tells the story of the Roman city that stood exactly where you are standing. Long before the cathedral, long before the medieval merchants, this ground was a Roman provincial capital on the edge of the empire, facing the free Germanic tribes across the Rhine.

That Roman city had a long name — Colonia Claudia Ara Agrippinensium. The word Colonia survives today as Köln, the German name for Cologne. The rest of the name honours Agrippina the Younger, a Roman empress who was born here. In the middle of the first century, the settlement was raised to the rank of a Roman colony, a city with full Roman legal status. From then on, it grew into one of the most important towns in the northwest of the empire.

Here is the first surprise. The museum was not placed here by chance. It was built around a treasure that was found in the ground right beneath it. In 1941, during the Second World War, workers were digging an air-raid shelter beside the cathedral. Their shovels hit a floor of tiny coloured stones. It was a Roman mosaic, still lying where its makers had set it, in the dining room of a wealthy Roman townhouse.

This is the Dionysus Mosaic, named after the Greek and Roman god of wine and celebration. It was made around the third century. Millions of small stone and glass pieces form scenes of dancers, musicians, and drunken companions of the god. The colours are still clear — reds, ochres, blues, and creamy whites. Because the mosaic could not be moved without great risk, the city decided to build the museum on top of it. The museum opened in the 1970s.

The second surprise is something many visitors miss. You do not always need to go inside to see it. The architects gave the building large windows facing the square. If you walk along the glass and look down and in, you may see the mosaic floor from the street. Generations of passers-by have pressed their faces to this glass. It is one of the few places in Europe where a Roman floor can be glimpsed on an ordinary walk to the shops.

The other giant of the collection is a tomb. It belonged to a Roman veteran named Lucius Poblicius, who served in the legions and settled in Cologne. His family built him a tall stone monument beside a road outside the city walls, as Romans did. Over the centuries, the tomb collapsed and its blocks were buried. Reassembled inside the museum, it rises several storeys high, with carved figures standing in its upper level.

The story of its discovery is a quiet delight. In the 1960s, two brothers were digging in the cellar of their family home in the south of the city. They began to find carved stones. Rather than abandon the work, they kept digging, piece by piece, over a long period. Their patience gave Cologne one of the finest reconstructed Roman tombs north of the Alps. It is a reminder that this city still sits on top of its past.

The museum is also known for its Roman glass. Cologne was a major glass-making centre in Roman times, and the collection is among the largest of its kind anywhere. There are delicate bottles, drinking cups, and perfume flasks in pale green, deep blue, and amber. One famous type is the cage cup — a vessel carved from a single thick piece of glass, with an outer net of glass held away from the cup by tiny bridges. It shows astonishing skill.

Beyond Rome, the collection follows the people who came after. When Roman power faded, the Franks, a Germanic people, took control of the region. Their graves have given up jewellery, brooches, weapons, and glass beads. Some brooches are set with red garnets in fine gold cells. These objects help explain the museum's name. Romano-Germanic means the meeting of two worlds — the Roman empire and the Germanic peoples who lived on its borders and later inherited its lands.

A practical note. The main building has been closed for an extended renovation in recent years. During this time, part of the collection has been shown in a temporary exhibition elsewhere in the city centre. Before you plan your visit, check the museum's current arrangements. Even when the doors are closed, this square is worth your time. The windows, the surrounding Roman remains, and the cathedral itself make this one of the best places to sense how deep Cologne's history goes.

And the Roman city is not only behind glass. Look around the cathedral area and you can find fragments of it in the open air. Near the cathedral stands part of an arch from the Roman north gate of the city. Nearby, sections of the Roman street level and old drainage have been uncovered over the years. The modern square sits several metres above the Roman ground. Every step you take here is on top of layers of earlier life.

So before you leave, look once more at the plain glass front of the museum. Then look up at the dark stone towers of the cathedral rising behind it. Two thousand years of this city stand side by side here — a Roman dining room under a modern roof, a medieval church above a Roman street. As you walk away across the square, listen to the trams and the voices around you. People have filled this place with noise for a very long time.