Pantheon
A 2,000-year-old temple so perfect engineers still study it.
The Pantheon is one of the best-preserved buildings from ancient Rome — a temple completed around 125 AD under Emperor Hadrian, later converted into a Catholic church, which is the main reason it survived when so many other Roman monuments didn't. It has stood for nearly two millennia in the middle of what is now a busy piazza in central Rome, and it remains one of the most technically astonishing structures ever built. The dome — a perfect hemisphere with an open 9-metre hole at the top called the oculus — was the largest in the world for over 1,300 years and is still the world's largest unreinforced concrete dome.
When you walk through the massive bronze doors, the scale hits you immediately. The interior is a single circular room, and if you were to place a perfect sphere inside it, that sphere would touch the floor and the oculus simultaneously — the height and diameter are exactly equal at 43.3 metres. Light pours through the oculus and moves across the walls and floor as the day progresses, acting like a kind of sundial. The tombs of two Italian kings (Vittorio Emanuele II and Umberto I) are here, as is the tomb of the Renaissance painter Raphael — a remarkable mix of ancient, royal, and artistic history in one room.
Since 2023, entry requires a pre-booked timed ticket through the official Pantheon website (coepantheon.it), which costs a modest fee for most visitors. The change was made to manage crowd numbers, and it has genuinely improved the experience — gone are the worst of the crush crowds. Come as early in the morning as possible for softer light and fewer people. The piazza outside, Piazza della Rotonda, is always lively and surrounded by cafés, but skip the tourist-trap spots ringing the square and walk one or two streets away for a better coffee at a fraction of the price.
