On Monday, we had the grace of having Mass in the Clementine Chapel. For those who don't know, this chapel is down in the Crypt of Saint Peter's Basilica. The chapel is built out from the location where Saint Peter's bones, for centuries, were believed to have been buried. Excavations of this last century, to the extent that the science of archaeology and history can, have proved this to be true. 
Saint Peter's bones, now encapsulated in NASA-donated air-sealed cases, are located just behind the wall where the ad orientem altar is built; in the picture on the right they are just behind the "window" in the bottom part of the altar. More pictures of this chapel and more information can be found here.
The chapel is called "Clementine" because it was renovated by Pope Clement VIII in the 16th century. Apparently, all of the gold in the chapel came from the first shipment of gold in the new world, being donated by King Ferdinand and Queen Isabella of Spain.
It was a great grace. I had the honor and privilege of serving as deacon at the Mass, as well as preaching. One thinks of a certain burden which is upon the preacher: all of the popes, cardinals, bishops and priests who have said Mass there. Indeed, every time at Mass we are specially in the presence and before the reality of our Lord who judges us for our stewardship of his gifts and graces, but the location and gravity of the reality of preaching in this place creates an entirely new (yes, existential) reality. And this is only proper, for it is profitable to our devotion and for our salvation. I think if one didn't recognize a special onus with preaching there, his perception is askew.
But, I gave it what I had, according to reason, with the intent of my will and the grace of God.
The same goes with simply serving at this altar and being able to partake in the sacrifice of the Mass at this holy place. I was humbled and could only beg the grace to follow the example of Saint Peter.
