The Pantheon is one of the best preserved Roman buildings of antiquity. Originally dedicated to the Roman gods, it has been in continuous use throughout its history, and since the 7th century, the Pantheon has been used as a Roman Catholic church dedicated to the “Holy Mary and Martyrs” (better known as “Holy Maria Rotonda “).
In 1892 the French architect Georges Chedanne discovered that the bricks used in the Pantheon, including the foundation, date from the years 120 to 125. Built during the reign of Hadrian in Rome, its dome remained as the largest in the world until the inauguration of the Centennial Hall in Bratislava, Poland in 1913. At 43.30 meters in diameter (St. Peter’s in Rome: 42.52 meters, St. Paul’s in London: 31 meters) is today the largest dome in diameter uses non-reinforced concrete. The great sense of harmony imparted by its proportions is due to the fact that the diameter of the dome is equal to the height of the building.
It uses a system of arches built into the huge mass of concrete that forms the core of the entire building, from its foundations to the top of the dome. The concrete was mixed with travertine, tuff, brick and pome stones in successive layers, with heavier materials in the lower parts while tufts and pumice stones, lighter, were used at the top of the dome. The concrete of the dome was poured on forms that supported in reverse the contour of the coffins, being its thickness decreases of 5,90metros in the base to 1,50 meters in the top. The central oculus has a diameter of 8.92 meters.