St Peter's Basilica

St Peter's stands over what Roman tradition and modern excavation agree is the grave of the apostle Peter, executed in Nero's circus a few dozen metres away around 64 AD. Constantine built the first basilica over the spot in the 320s; the current one took 120 years (1506–1626) and every great architect of the Italian Renaissance — Bramante, Raphael, Michelangelo (who designed the dome at age 71 and refused payment), Bernini (the bronze baldachin and the colonnaded piazza that gathers you in like arms).

Entry to the basilica is free — you pay in queue time. Security peaks between 10 AM and 4 PM at over an hour; at 7 AM opening you walk straight in, and the nave in early light with almost nobody in it is one of the great free experiences in Europe. Wednesday mornings the piazza hosts the papal audience and the basilica opens late — plan around it. Dress code is enforced without appeal: shoulders and knees covered, for men too.

Inside, the checklist: Michelangelo's Pietà (first chapel on the right, behind glass since a hammer attack in 1972 — carved when he was 24), the bronze St Peter with its foot worn smooth by six centuries of pilgrim touches, Bernini's baldachin over the papal altar, and the sheer calibrated vastness — brass floor markers show where every other great cathedral would end inside this one.

The dome climb is the paid extra and it's superb: a lift or 231 stairs to the terrace, then 320 more squeezed between the dome's two shells, leaning with the curve, to the lantern and the definitive view of Rome — Bernini's piazza directly below like an architectural drawing. Go straight up at 7:30 AM before the basilica queue forms; you exit the climb inside the church.