The Pantheon Explained: Dome, Oculus, Niches and Tombs

A guided visit that takes the building apart in four pieces and puts it back together. First the portico, with its granite columns, each shaft a single block of Egyptian stone. Then the dome, the largest ever cast in unreinforced concrete, which is still true after nineteen centuries and is not a compliment so much as a measurement. The oculus is nine metres across and open to the sky. It lights the room, and that is the answer everyone knows. The guide covers the other reasons it is there, which have to do with the weight at the crown of a dome and with what a temple to all the gods was supposed to be open to. The niches around the wall held gods and now hold altars and tombs, and the guide explains what changed and what did not when the building was consecrated. The burials are Raphael, Victor Emmanuel II, Umberto I and Margherita of Savoy: a painter and three members of a royal house that ruled for less than a century, in a room built by an empire. How the Pantheon came through the fall of Rome, and why architects are still copying it, closes the visit.