Perhaps one of the best known and most preserved of all ancient Roman buildings is the Pantheon. It was originally commissioned by Marcus Agrippa as a part of a complex of buildings created by him on his own property (Campus Martius). It initially was built between 29-19 BCE and later rebuilt by Emperor Hadrian around 126 AD. The Pantheon has been in continuous use throughout its history. Since the 7th century, it has been used as a Catholic Church , known as Santa Maria Rotunda. For those who are fans of Dan Brown's books, Raphael's tomb is indeed located within the Pantheon (and not elsewhere as suggested by "professor Robert Langdon").
The inscription on the front of the Pantheon, which translates to "Marcus Agrippa, so. Of Lucius, made [this building] when consul for the third time" is the only piece left of the original building. Having originally been built of wood, the Pantheon burned down three times before it was finally rebuilt of stone.
In its current use as a Catholic Church, this is the main altar area.
The height to the Oculus is the exact same as the diameter of the interior circle, 43.3 meters (142 feet). Being open to the outside, when it does rain, the interior floor does get wet. On Pentacost Sunday, Vatican staff pour rose petals through the Oculus, falling to the floor like rain, signifying the descent of the Holy Spirit upon the Apostles. The dome of the Pantheon is larger than that of St. Peter's Basilica, and is the world's largest unreinforced concert dome.
Many folks visiting the Pantheon see the front of the building and the interior only. However, there is much more to see of the exterior, if you choose to explore the sides and back. In part II, we will do just that.