From gladiators to football players

Going back to a time, when Paris was still called 'Lutetia' and the amphitheater Arènes de Lutèce was built in the 1st century AD. It is in the middle of today's Paris and quite a surprise to find such a site. It is large, originally having a capacity for 15'000 people. In later centuries becoming a cemetery, then filled in completely and sleeping for centuries.

It was only discovered around 1860 when the rue Monge was built and a tram depot was planned to be built there. Fortunately the value was recognized and the area protected.

Link: some further reading on Wikipedia