Pantheon

The Pantheon is the best-preserved building of Roman antiquity — and one of the most architecturally ingenious structures in human history. Built under Emperor Hadrian around 125 AD, the free-standing concrete dome has a diameter of 43.3 meters — a record that remained unmatched for 1,300 years (until Brunelleschi's dome in Florence). The circular opening at the apex of the dome (the oculus, 9 m in diameter) is the only light source — when it rains, water falls through the opening onto the slightly inclined marble floor and drains through holes.

Inside lie the tombs of two Italian kings and the painter Raphael (1483–1520). The inscription on his tomb reads: "Here lies Raphael, during whose lifetime nature feared to be outdone, and at whose death feared it would die itself."

Since 2023, admission is no longer free — a fee of €5 is charged. Nevertheless: The Pantheon is a must. Especially impressive in the rain or when a single ray of sunlight falls through the oculus and traverses the interior.