Centro Storico: the Pantheon and Piazza Navona
The best-preserved building of antiquity, a baroque square, and the lanes that thread the two. This is a Claude-drafted route awaiting the editor's walk.

1. Piazza della Rotonda
Come early, before the square fills. The Pantheon's portico faces you across the *piazza* and the *Fontana del Pantheon* in front of it — sit on the fountain step with a coffee and look up at the pediment for a while before going in.

2. The Pantheon
Walk in and stand directly under the *oculus* — the open eye in the dome, nearly two thousand years old and still the largest unreinforced concrete dome on earth. Entry is ticketed now; go at opening to have the floor to yourself. Raphael is buried in the wall to your left.

3. Sant'Ivo alla Sapienza
Duck into the courtyard of the old university on Corso del Rinascimento for Borromini's spiralling lantern — a corkscrew of stone you'd miss from the street. The church itself keeps short, odd hours, but the courtyard is reward enough.

4. Piazza Navona
Built on the shape of Domitian's stadium, which is why it's a long oval rather than a square. Bernini's *Fontana dei Quattro Fiumi* is the centre; the figure shielding its eyes is supposedly recoiling from Borromini's church opposite — a feud in marble. Walk the full length.

5. Sant'Agostino
A few minutes north, slip in for Caravaggio's *Madonna dei Pellegrini* — the one with the pilgrims' dirty feet pointed straight at you. Bring a coin for the light box; it's the only way to see it properly.

6. Sant'Ignazio
End at the church with the painted-on dome. Stand on the brass disc set in the floor and look up: the flat ceiling becomes a soaring dome through sheer perspective trickery. Step off the disc and watch it collapse back to a painting.

Centro Storico: the Pantheon and Piazza Navona