The Vatican Necropolis

Beneath St Peter's floor runs the most consequential excavation in Christendom: the Scavi tours descend into the Roman necropolis over which Constantine raised his basilica - an intact street of pagan and early-Christian mausoleums, frescoed and mosaic-floored, sloping toward the aedicula memorial that second-century Christians raised over what they held to be Peter's grave, the spot the altar has crowned ever since. Access is deliberately scarce: small groups by advance application to the Scavi Office, guided through the warm, close passages to the graffiti wall and the relic niche. It is ninety minutes of vertical time-travel, ending directly under the dome's axis.

What you actually see

• The mausoleum street - frescoed Roman tombs in file.
• The aedicula memorial - the second-century marker under the altar.
• The graffiti wall - pilgrim scratches naming Peter.
• The axis moment - standing beneath dome, altar and grave aligned.

When to go

Year round by application - write to the Scavi Office months ahead; the quota is tiny and the confirmation its own small miracle.

Honest expectations

The passages run warm, close and stair-laced - claustrophobia and mobility limits should weigh honestly; photography is prohibited throughout and the rule absolute.

Nearby

The basilica above, the crypt's papal tombs and the square.