Visiting Rome with limited time? Focus on the historical layers. The must-see five are the Colosseum, St. Peter's Basilica, the Pantheon, Piazza Navona, and Trevi Fountain. Experience ancient grandeur and Baroque beauty efficiently. Prioritize transit (take a taxi to St. Peter's) and check for the original ground level outside the Pantheon! This curated list ensures maximum impact in minimum time.