Just a ten-minute walk from the Colosseum, you’ll find a fascinating underground crypt that hardly anyone knows.
It’s hidden beneath the Church of San Martino ai Monti, an ancient church dating back to the 4th century.
Once inside, look for the altar. There’s a passage right behind it that leads downstairs, where you’ll discover the many lives this place has lived. First, it was a thermal bath, then an indoor market, and eventually a Christian place of worship.
Here’s a closer look underground.
📍You’ll find it in Viale del Monte Oppio, 28
