The Vatican is a compact but busy place centered on St. Peter’s Basilica and the Vatican Museums, so plan ahead: buy timed-entry tickets for the museums online and allow at least two to four hours, because lines and crowds are common. Dress modestly with shoulders and knees covered to enter churches, expect airport-style security checks and bag inspections, and know that photography is strictly forbidden inside the Sistine Chapel. If you want the city view, climb St. Peter’s dome — there is an elevator partway but the remaining stairs are steep and narrow, so wear good shoes and bring water. Avoid street touts selling “skip-the-line” tickets and get tickets from the official site or a reputable seller, and if you want to see the Pope try to reserve free tickets for the Wednesday Papal Audience in advance.