The Arènes de Lutèce is a Roman amphitheatre with a football pitch in it. What you walk into is roughly half an amphitheatre. Old men play boules along one side under the trees, children play football on the arena floor where animals were fought, and people sit on the terraces where Roman audiences sat. The backs of apartment buildings stand on three sides, at about the height of the top row. It is one of only two Roman structures still standing in Paris.
It was cut into the hillside in the first century, when the Roman town on the left bank was called Lutetia. It was built to do two jobs at once: plays on a stage at one end, fights and animal shows in the oval arena in front of it. Seating is estimated at about fifteen thousand, more people than are thought to have lived in the town. It went out of use, filled with earth, and by the Middle Ages nobody knew it was there. Men digging foundations for a tram depot cut into the terraces in 1869, and Victor Hugo campaigned to save what was left.