There are many articles about the Church being literally built on Peter. Here is an article about St. Peter’s burial grounds:
An excerpt from the second link:
The body of St. Peter is said to have been buried immediately after his martyrdom, upon this spot, on the Vatican hill, which was then without the walls and near the suburb inhabited by the Jews. The remains of this apostle were removed hence into the cemetery of Calixtus, but brought back to the Vatican. Those of St. Paul were deposited on the Ostian Way, where his church now stands. The tombs of the two princes of the apostles, from the beginning, were visited by Christians with extraordinary devotion above those of other martyrs. Caius, the learned and eloquent priest of Rome, in 210, in his dialogue with Proclus the Montanist, speaks thus of them:** “I can show you the trophies of the apostles. (See excerpt from next article about “trophy”) For, whether you go to the Vatican hill (Peter), or to the Ostian road (Paul), you will meet with the monuments of them who by their preaching and miracles founded this church.”**
Another article excerpt:
**ROME - **There’s a reason St. Peter’s Basilica was built where it stands. A reason Michelangelo’s dome, Bernini’s spiral-columned canopy and the main altar are all precisely where they are.
It’s found in a single verse from the Gospel of Matthew: ``And I say to thee: That thou art Peter; and upon this rock I will build my church.’’
For 1,700 years, dating back to the construction of the original St. Peter’s by the emperor Constantine, Roman Catholic tradition has held that the main altar stands directly over St. Peter’s tomb. Today, a tiny fraction of the hundreds of thousands who visit St. Peter’s each year are guided back through time, along an ancient subterranean path between two rows of fragile pagan and Christian tombs to view the evidence:** a small pillar reputed to be part of one of the earliest monuments over the saint’s grave,** a wall that once bore a faint Greek inscription sometimes translated as ``Peter is here,’’ and 18 small bones enclosed in two plastic glass boxes, viewed through a small ragged hole in a wall 33 feet below the floor of the modern basilica.
And…Near the end of the excavations, visitors come to a supporting wall for the left side of the spiral canopy over the main altar of St. Peter’s. Next to the supporting wall is the small white pillar that remains from the Trophy of Gaius.