Pantheon

Built between 113 and 125 AD under Emperor Hadrian, the Pantheon is the most complete ancient Roman building anywhere — its dome remained the largest in the world for 1,300 years until Brunelleschi finished Florence's Duomo in 1436. The 9 m wide oculus at the centre of the dome is the only light source; rain falls inside and drains through 22 holes in the slightly tilted floor. It became a Catholic church in 609 AD, which is why it survived.

Two Italian kings (Vittorio Emanuele II and Umberto I) are buried here, plus the Renaissance painter Raphael, who died in 1520 at age 37. His tomb sits to the left of the altar with the Latin inscription "Here lies Raphael, by whom the great mother of all things feared to be conquered while he lived." Active masses still happen on Sundays at 10:30 and 17:00 — the building serves as the church of Santa Maria ad Martyres.

Free admission ended in July 2023. Adult ticket is now €5 (under-25 EU residents €2, under-18 free). Buy online at museiitaliani.it or at the door — queues are usually 10 minutes. Sunday mornings are crowded with mass-goers (free during service). The Piazza della Rotonda outside has Bernini's 1711 elephant obelisk and several mediocre cafés — go to Sant'Eustachio Il Caffè (3 min walk) for proper Roman espresso.