The Pantheon ("Temple of all the gods") is a temple dedicated to the gods of Olympus. It was built by Emperor Hadrian between 118 and 128 AD, after the fire of AD 80 and 110 that damaged the previous construction. The dome has a diameter of 43 meters, and it was built with a single cast. The opening at its top is called the "oculus". According to the tradition, the rain does not enter in the Pantheon for the so-called "chimney effect": in reality it is a legend associated with the past when many candles were lit in the church produced a stream of warm air rising up and meeting with the rain, thus eliminating the perception of water entry. The construction of the dome was made possible thanks to a series of tricks that helped to light the structure, including the use of ever lighter materials gradually upward in the lower layer are in fact layers of concrete and chips of brick, concrete and scales are going up tuff, and finally the top is concrete mixed with volcanic lava ground. The building was saved from destruction in the Middle Ages because in 608 the Byzantine Emperor Phocas gave it to Pope Boniface IV (608-615), who turned it into a Christian church. This was the first case of a pagan temple converted into a Christian church. This fact makes it the only building of ancient Rome to have remained virtually intact and in continuous use for religious purposes since the time of its foundation. Since the Renaissance the Pantheon has been used as a tomb. It preserves, among others, the remains of the painters Raffaello Sanzio and Annibale Carracci, the architect Baldassare Peruzzi and the composer Arcangelo Corelli. There are also the tombs of the kings of Italy Vittorio Emanuele II and Umberto I and Queen Margherita.