Pantheon Small-Group Tour Meeting by L'Antica Salumeria

A small group, a guide, and the one Roman monument of its size that came through two thousand years without collapsing. Why it survived is the question the tour opens with, and the answer is partly engineering and mostly continuous use. The meeting point is Piazza della Rotonda 4, next to the shop L'Antica Salumeria, in the square where the obelisk stands. Inside, the dome measures 43 metres across and the oculus at its centre is the only opening, which is enough to light the whole room. The guide explains how a span like that was cast in concrete with nothing reinforcing it. Then the change of religion. Pope Boniface IV had the building consecrated as Santa Maria ad Martyres, the church of St Mary and the Martyrs. The tradition that cartloads of bones were brought up from the catacombs for the occasion is worth knowing about mainly because it is not contemporary: it first appears about a thousand years later, and the early sources say nothing of it. The dedication is real, the wagons are folklore. Raphael is buried here, and so are the kings of Italy.