Ancient City Ostia-Capitolium

The Capitolium stood at the Forum of Ostia and represented one of the most significant buildings of the ancient city. The building was erected under Hadrian, around 120 AD.

The brick-built temple stood on the north side of the Forum and blocked traffic there, as it was built directly on one of the city's main streets. It was a Roman podium temple, meaning the building stood on a high base. This was accessible via 22 steps and measured 35 x 15.5 m in plan. This podium perhaps symbolized the Capitoline Hill, on which the Capitolium of Rome stood.

The front of the temple was structured by six columns. In total, the ruins still stand about 17 m high today. In antiquity, the temple was more than 20 m high. The actual cella behind the columned facade consisted of a large room, at the back wall of which were three cells, probably dedicated to the Capitoline Triad of Jupiter, Juno, and Minerva. However, there is no conclusive evidence that these deities were actually worshipped here, and the identification is based on comparisons with temples in other parts of the Roman Empire. It has therefore even been suggested that the temple was dedicated to Vulcanus, the patron deity of the city. However, inscriptions indicate that the temple of Vulcanus was renovated in 112. This date cannot be reconciled with the construction period of the Capitolium. The construction period around 120 AD is reliably attested by stamped bricks.

The interior of the cella was richly decorated with marble. Almost nothing of this remains today. 19th-century drawings show that the floor was decorated with a chessboard pattern. Niches are found in the walls of the cella.

In front of the temple stood a marble-clad altar, whose relief decoration shows weapons.