The Pantheon
The original building, square, was built by Agrippa, son of Augustus in 27 BC for the glorification of the gens Iulia, and was dedicated to the seven planetary deities (linked to the cult of the planets and suspected: Sun, Moon, Venus, Saturn, Jupiter, Mercury, Mars) and particularly to Mars and Venus. The building was damaged by fire in 'AD 80, restored by Domitian, was again destroyed at the time of Trajan (110 AD). It was finally rebuilt under Hadrian between 118 and 125 AD in a radical way by rotating the façade of 180 °.
The 'building is composed of a cylindrical wall topped by a domed ceiling made of concrete, and a porch with 16 columns of pink granite and gray under a large triangular pediment. Below, in the thickness of the walls, open 7 large niches between two Corinthian columns, topped by 8 niches, decorated in marble. The huge bronze door that closes the marble portal, is perhaps the original, much restored. The dome (made of concrete cast on a single rib of wood), hemispheric, is as high as the radius of the cylindrical body, the shape of the temple is to be that of a hemisphere superimposed on a cylinder of equal height and equal haul.
The dome is decorated with five rows of drawers are narrowing concentric circular opening up the ends. The central portico, semicircular, is preceded by two columns, the other exedras are three on each side: the central one with a semi-circular recess on the bottom, the side with three rectangular niches: in front of each of these two monolithic columns support the architrave. Among exedra and the other are some kiosks consist of two columns supporting alternately triangular gables or section of a circle. Above began the second order, which has been rebuilt once. In the floor with squares and circles inscribed - fully preserved in its design, despite some restoration - reappeared the same marble used in architectural decoration: porphyry, granite, pavonazzetto antique yellow.
The number of niches and the niches were occupied by statues of deities: the building was, in fact, dedicated, as the name implies, all the gods. Its original meaning was rather that of a dynastic temple, as indicated by the presence of the statues of the gods of the dynastic Julio-Claudian family (Mars, Venus and the same Divine Julius). In the Hellenistic period as the Pantheon has a clear meaning: that of a temple dedicated to the deified kings and other gods associated with him. In the Pantheon of Agrippa, however, the statue of Augustus was not in the cell, but in the porch.