Even if you're not particularly drawn to religious history, St Peter's Basilica is worth visiting for purely architectural, artistic, and engineering reasons that make it one of humanity's greatest architectural achievements.

A scale that's hard to grasp from outside

St Peter's Basilica is the largest church in the world by interior floor area, and sits within Vatican City, the smallest independent state in the world by both area and population. The massive dome crowning the building was designed by the architect and artist Michelangelo, and remains to this day one of the standout engineering achievements in the history of European architecture, its height making it visible from many parts of Rome.

What's inside exceeds expectations

The interior is decorated with works by some of the greatest Renaissance and Baroque artists, most notably Michelangelo's "Pietà," which he sculpted in his twenties, depicting the Virgin Mary holding the body of Christ — considered one of the most refined and visually powerful sculptures in the history of Western art, now protected behind glass after being vandalized in 1972.

Entry is free, but planning is essential

Unlike the Vatican Museums which require a paid ticket, entry to the Basilica itself is free — which is exactly what makes the lines so long during peak season, sometimes stretching an hour or more just for security screening. Arriving very early (before 9am) or in the later afternoon hours noticeably cuts the wait. Climbing the dome (for a separate additional fee) gives you a sweeping panoramic view over St Peter's Square and the whole city of Rome, but requires climbing hundreds of narrow steps, so decide in advance whether that's physically manageable for you.

The dress code many overlook

Visitors are required to cover shoulders and knees to enter, no exceptions, for all ages and genders. Many visitors get turned away at the door over this simple detail despite having traveled from far away, so bring a light scarf or a spare cover-up even on hot summer days.

St Peter's Square itself

Before or after visiting the Basilica, take time in the massive forecourt designed by Bernini, with its double oval colonnades embracing the space like open arms — a deliberate symbolic design representing the Church's embrace of visitors from around the world.

One last tip

Combine the Basilica and Vatican Museums into one day if possible, since both sit within roughly the same complex, but plan enough time — at least half a day — as this isn't a place you can rush through.