Overview
Rome layers ancient, papal, and Baroque collections across the Capitoline Hill, Vatican City, and dozens of churches and palazzi. The Vatican Museums and Sistine Chapel alone require half a day with advance booking.
Suggested itinerary
Day 1: Vatican Museums + Sistine Chapel (book 8 AM slot) → St Peter's → Castel Sant'Angelo. Day 2: Capitoline Museums → Roman Forum/Palatine → Colosseum exterior. Day 3: Galleria Borghese (book ahead) → Villa Giulia (Etruscan) → Trastevere.
Best time to visit
November–March for shorter Vatican queues. Never visit Vatican on free last-Sunday-of-month unless you enjoy 3-hour waits.