Piazza Navona, Rome's most beautiful baroque square, has an unusual shape — long, narrow, with curved ends. That's because it isn't built ON a Roman stadium. It IS a Roman stadium. In 80 AD, Emperor Domitian built a stadium for Greek-style athletic competitions (foot races, wrestling, discus) that seated 20,000 spectators. The arena was 275 meters long. When Rome's medieval buildings grew over the ruins, they simply built on top of and into the stadium's arches. The piazza's shape exactly follows the arena floor. And 5 meters below the northern end, you can descend into the original stadium corridors and see the travertine arches, brick vaulting, and the scale of what's hidden beneath one of the most visited squares in Rome. Rome guide → · Hidden Rome →
Plan my Rome trip →The entrance is at Piazza di Tor Sanguigna 13 (just north of Piazza Navona — most people walk past it). You descend to the original ground level of 80 AD and enter the stadium's substructures: travertine arches and pillars that supported the seating above, brick corridors that athletes and spectators used, and the curving walls that trace the arena's original shape. The space is atmospheric — dimly lit, ancient stone, the knowledge that 20,000 Romans were cheering right above where you're standing. Multimedia installations project reconstructions of the original stadium in use. A small museum displays finds from excavations beneath Piazza Navona.
Look for the arches from above too: walk along Via di Tor Sanguigna and the surrounding streets — many building facades incorporate visible Roman arches from the stadium's outer wall, now functioning as shop entrances and garage doors. The Palazzo Pamphilj (Brazilian Embassy) on Piazza Navona sits directly on the stadium's seating tiers.
Address: Via di Tor Sanguigna 13 (entrance on the small street behind Piazza Navona's north end). Tickets: €10 (combo tickets with other sites sometimes available). Hours: 10am-7pm (last entry 6pm), closed Tuesdays. Duration: 30-45 minutes. Combine with: Piazza Navona (directly above — Bernini's Fountain of the Four Rivers, Borromini's Sant'Agnese), Pantheon (3min), Area Sacra Largo Argentina (5min), Campo de' Fiori (5min).