The Roman Pantheon built as a temple by Marcus Aggrippa around 25 BCE and dedicated to the Roman Gods is known for its dome, which was the largest until 1436. The current building was constructed by the Emperor Hadrian during the period 118 to 128 AD following the previous ones be destroyed by fire. In 609 AD it was converted to a church and contains the tombs of a number of Italy’s monarchs.
The Pantheon has the largest un-reinforced dome in the world and was the largest dome until the completion of the Duomo of Florence in 1436. Today it ranks twelve in size. Constructed of un-reinforced concrete it has a height of 43.3m which equals the dome's diameter. Two identical domes placed together would make a perfect sphere.
The Pantheon was built originally as a temple by Marcus Aggrippa, Consul of Rome and son-in-law of the Emperor Augustus around 25 BCE and was dedicated to the Roman Gods (“Pan" means everything, "theon", divine). This is confirmed by the inscription above the entrance which states that "Marcus Agrippa, son of Lucius, in his third consulate, made it."
This refers to the original temple and not the current one. Aggrippa’s temple was rectangular in shape and was destroyed by fire in the rein of Emperor Domitian, which was then rebuilt by him, although that too was destroyed by fire. The one that exists today was constructed by the Emperor Hadrian during the period 118 to 128 AD and the examination of the building indicates the level of the ground when it was first constructed.
The best preserved of all ancient Roman buildings, it owes its preservation to the fact that in 609 AD it was given to Pope Boniface IV who converted it to a church and dedicated it to the Virgin Mary placing the bones of Christian martyrs under the High Altar.
In 1624 bronze was removed from the beams in the Pantheon for the construction of the baldacchino in St Peters Basilica. To compensate for the removal, Pope Urban VIII (1623-1644) added two bell towers designed by Bernini which became known as "the donkey ears of Bernini;" these were demolished in 1883.
At the rear of the building is the Sacristy and a Chapel in a single storey extension to the rotunda.
The portico has three ranks of large granite Corinthian columns (eight in the first rank and two groups of four behind). The capitals of the columns are all damaged, except for the three columns on the eastern side. These three columns were replaced in 1666 with columns taken from the Baths of Severus Alexander.
The pediment was originally decorated with a sculpture and holes may still be seen for the clamps which held the sculpture. Within the walls at the back of the portico were niches, which probably held statues of Caesar, Augustus and Agrippa, or Jupiter, Juno and Minerva - known as the Capitoline Triad.
The main part of the building is circular with the entrance through a rectangular structure linking the portico with the rotunda. The entrance doors to the Pantheon are 7m high (22 feet) and made out of bronze, these were once covered with gold.
Inside the Pantheon is a coffered, concrete dome; the concrete consisting of hydrate of lime, pozzolanic ash, pumice with small pieces of rock (around 100mm in diameter) which was constructed over a formwork, similar to the technology used today.
At the centre of the dome is the oculus, which measures over 8 metres (27 feet) across and the source of light in the building.
Any rain that enters collects in a drain in the centre of the floor. On the 21st June (the summer equinox), the sun rays shine from the oculus through the front door.
Along the interior walls can be seen marble columns, niches with memorial portrait busts, the seven arched recesses originally housed statues of the seven ancient Gods. Today, the walls of the Pantheon have lost much of their splendour. Originally they were covered by Pentelian white marble and stucco, traces of these can still be seen.
Interior of the building showing the coffered, concrete dome and circular shape of the building.
Opposite the entrance is the High Altar and above the altar is a 7th century icon of the Madonna and Child which dates from when the temple was first converted to a Christian church. Although rare today these were common in Roman churches at that time.
Located inside the Pantheon are a number of tombs, these include the tombs of Vittorio (Victor) Emmanuel II, first king of a unified Italy;
Also buried there is his son and successor, King Umberto I.
Although Italy has been a "Republic" since 1946 members of the Italian monarchist organization holds a vigil over their tombs.
Also buried within the Pantheon in 1520 is the Italian artist Raphael, he worked in some of the Papal apartments in the Vatican and his work typifies the classical phase of the Renaissance.
The Pantheon remains a church to this day and is still used for the celebration of mass, marriages and on special occasions.
To see more photographs and take a virtual tour of the site click on the photoshow below.