[what's up]

I heard that one can get a special pass to see some of this subterranean stuff under St. Peter's.

I wonder if that's true.

[what's up]

Visitors can have a guided tour of the grottoes by appointment

Whoops...I just answered my own question.

But I still wonder if this includes Peter's tomb.

[WilliamWallace1999]

Yes, you can. Been there and done that. You have to request tickets two weeks in advance and pass basic background checks. We walked several hundred yards through the Necropolis excavations and saw the tomb of Peter. Bones and teeth were found that carbon date to the first century and the teeth suggested and age in the 70’s-80’s. Still it is a matter of faith, but I was very moved despite my questioning nature.

[NYer]

I heard that one can get a special pass to see some of this subterranean stuff under St. Peter's.

Visit of the Excavations below St. Peter's Basilica.

[vladimir998]

You can go on a public tour for not too much money. I did it last February. Fascinating stuff.

All that is really required is a written request for tickets:

http://www.vatican.va/roman_curia/institutions_connected/uffscavi/documents/rc_ic_uffscavi_doc_gen-information_20040112_en.html

[StAthanasiustheGreat]

Yes, its called the Scavi.