First of all, catacombs are a peculiar phenomenon in the area around Rome; they're always outside the city, as all burials had to be, but it's a peculiar geologic formation.

Beneath Rome's iconic landmarks lies a hidden worldMuch of ancient Rome, of course, "remains hidden under visitors' feet," said Tony Perrottet in Smithsonian. Visit the Pantheon or the Colosseum ...

Much of ancient Rome, of course, "remains hidden under visitors' feet," said Tony Perrottet in Smithsonian. Visit the Pantheon or the Colosseum and you'll notice that the buildings' foundations ...