The Pantheon is a building of ancient Rome, in the historic center of Rome. Originally it was a temple dedicated to all the divinities, today it is a Christian Basilica.
It was built in 27 BC. by the architect Agrippa and after the fire that destroyed it, it was rebuilt in 1124 AD. by the emperor Hadrian.
It is composed of a circular structure joined to a portico (entrance) in Corinthian columns (8 at the front and 2 groups of 4 in the second and third row) that support the pediment.
The large circular cell, called the rotunda, is surrounded by thick masonry walls and 8 large pillars on which the weight of the hemispherical dome in concrete is distributed, which has a circular opening at its apex, called oculus, which allows the illumination of the internal environment.
The Pantheon is an example of a domed vaulted structure.
The dome has a diameter of 43,30 m and a weight of more than 5,000 tons and is the largest dome in the world, a prototype of the domes built in the following centuries (dome of St. Peter’s in Rome, Brunelleschi’s dome of the Florence Cathedral and dome of Hagia Sophia in Istambul).
Inside, it is decorated with 5 orders of 28 coffers of decreasing size from bottom to top.
The oculus that illuminates the interior of the church measures 9 m in diameter and is surrounded by a frame of tiles wrapped in bronze.
Despite this opening in the Pantheon, the rain does not penetrate, as the current of hot air present inside rises upwards and nebulizes the rain it encounters.
The construction of the dome was made possible thanks to a series of expedients that helped to lighten the structure: use of drawers, use of lighter materials towards the top, use of concrete mixed with tuff and volcanic lapilli.
The construction of the Pantheon was a masterpiece of engineering and architecture and reflects harmony and balance in the structure.