Excavations under St. Peter's Basilica

This article is really, really interesting and..... I can't say (my mom won't let me use cool in my posts.)
http://catholiceducation.org/articles/religion/re0735.html
It is about the excavations, under St. Peter's Basilica, also known as the scavi. While trying to make room for a spectacular tomb for Pope Pius XI it was necessary for the workmen to dig under St. Peters. While engaged in this noble task the workmen found a series of old tombs found to be a necropilis. Pope Pius XII organized a excavation of the site. Near the center was a altar shaped tomb, the wall behind was covered with graffiti. One piece of the graffiti seemed to say, Peter is here! So it seems that the tomb of St. Peter has come to light. It was found in exactly the place tradition said it would be.
To learn more about the scavi read this article.