The first thing that will draw your attention is its  large Latin inscription with bronze letters: M.AgrippaL.F.Cos. Tertium.Fecit ( “Marcus Agrippa, son of Lucius, Consul for the third time, built”). In fact, this inscription dates back to the first “version” of the Pantheon built by Agrippa, son of Augustus, in 27 BC.

What we see today, however, is the Pantheon completely rebuilt by Hadrian in 118-125, who wanted to keep on the front of the building the original inscription to which the scholars, for a long time, could not give a precise chronological position.

The Pantheon, in greek, is the place where all the gods meet. The function that it was supposed to have in ancient Rome is still uncertain. According to historians, it was built to house the statues of many gods of pagan Rome, but the name may also derive from the fact that the dome refer tothe sky. Agrippa  wanted to make a temple dedicated to the worship of the gods protectors of the Julian family, especially Mars and Venus.

When the Empire was destroyed the Pantheon was abandoned until the emperor of Byzantium, Foca, gave it in 608 to Boniface IV who consecrated it to the Virgin and all the martyrs. After it also had the function of small fortress and in 1652 Urban VIII Barberini eliminated the bronze coating of the colonnade beams from which he obtained 80 guns for  Castel Sant’Angelo and the four twisted columns of St. Peter’s canopy. When it was proclaimed the Unity, Pantheon had the function of sacrariumof the kings of Italy and the following  restoration  deleted the iron grating of the colonnade and the famous “donkey ears”, the bell towers added by Gian Lorenzo Bernini.

Tourists are amazed by the contrast between the squared entrance(Pronao), typical of the temples, and the immense rounded interior space typical of structures in Ancient Rome with a thermal function. The imposing colonnade , beyond which there are the portal and two niches probably  for the statues of Augustus and Agrippa, is decorated with 16 grey and pink granite columns  13 meters high. The walls of the round  are made by brick and the dome, the largest ever built in masonry, is made by conglomeration.

The dome of the Pantheon is one of the wonders of all time: a real technological gem that overcame 2,000 years of earthquakes. The dome in concrete, in fact, was built by following a pioneering technique that used materials always lighter from the bottom to the top. The architects used a particularly light conglomeration (opus caementicium) formed by mortar and travertine flakes, replaced as they went up to the top by lapillus and pumice stone. Under the stones there is a wooden structure with  many arches on which it is distributed the weight.

Inside the Pantheon there are seven semi-circular and rectangular niches made,  ribbed ancient yellow columns and niches with columns supporting tympanum; there is then an eighth niche, topped by an arch, which is situated opposite the entrance. In the vault adorned with five series of ceiling coffers, the only source of natural light is the bronze eye  of 9 meters and the floor has squares and circles pattern. In almost all niches there is something to admire: the first is the “Annunciation” fresco by Melozzo da Forli, in the second there is the tomb of Vittorio Emanuele II designed by ManfredoManfredi, in the sixth there are the tombs of Umberto I and Margherita di Savoia, in the seventh, called the Virtuoso of the Pantheon, there are funeral inscriptions of FlaminioVacca, Taddeo Zuccari and Perin del Vaga. Inside the Pantheon there is also the tomb of Raffaelloplaced under the Madonna del Sasso byLorenzetto.

It is said that in the Pantheon it never rains, although there is the huge oculus from which it should enter the water. In fact, in the Pantheon it rains like in all the houses where there is no roof. Not surprisingly, in the middle of the floor, just below the oculus, there are gutters that collect the rain.