Rome’s historic centre is a labyrinth of cobbled backstreets emerging onto open piazzas. But what you see on today’s street level tells just half the city’s story. Buried beneath Rome’s piazzas is a hidden world of mammoth ancient structures that rival the ground-level wonders of the Pantheon and the Colosseum and preserve some of the city’s most shocking secrets and stories. Here are some of our favourite.

Piazza San Cosimato & Rome’s Naval Colosseum
Locals know Trastevere’s Piazza San Cosimato for its bustling daytime market and evening open-air cinema. What few people know is that this square was once the site of naval gladiatorial battles (naumachia) inaugurated by the emperor Augustus in the first century BC.