If we’re measuring by interior volume, the winner is St. Peter’s Basilica in Vatican City. Yep, that glorious, marble-covered masterpiece in the heart of Rome.
Imagine fitting two Statues of Liberty inside it—that’s the scale we’re talking about. It can hold over 60,000 people standing up, which is more than most modern football stadiums.
But here’s the funny part: St. Peter’s isn’t technically a cathedral. It’s a papal basilica. A cathedral is the main church of a bishop, and St. Peter’s doesn’t have one. So, in strict church terms, it’s a bit of a cheat code.
