They're not for everyone though, so we take a critical look at where and what they are, what's worth seeing, a child's eye view and how to beat the crowds - all based on our own practical experience.
Use this page to decide whether it's a tour you want to take during your stay in Rome, or whether you'd prefer to sit in a square enjoying a 'Gelato'.
The first time we tried to find them we got completely lost. We expected the entrance to be somewhere off St Peter's Square - in fact it's not, it's up an adjacent street.
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