Descending along the Clivo Capitolino on the left we pass through the portico of the Dei Consenti, through the ruins of the Temple of Vespasian and what remains of the Temple of Concord, while on the right we pass the columns of the portico of the Temple of Saturn and the Arch of Septimius Severus. In the background we see the Baroque prospect of the Church of Saints Martin and Luke - built above the Secretariat of the Roman Senate - with its harmonious dome by Pietro da Cortona (who also designed within a beautiful guilt bronze altar located in the crypt) adorned with precious marbles coming from the Serretarium Senatus. Next to this is the small church of St Joseph of the Carpenters also called San Pietro in Carcere. This small, modest church is of great importance to Christianity it being built above the old Roman State Mamertine Prison. This gloomy, narrow prison was reserved for those condemned to death and once held within the Goth Jugurtha, Vercingetorix and the accomplices of Catilina, and was where St Peter baptized his jailers with the water from an underground spring. The Clivo Argentario between the Campidoglio and the Basilica Argentaria (a type of ancient Roman stock exchange), with its disconnected Roman pavement gives us the impression of being in a remote uncovered city. But this illusion soon vanishes as we arrive in the Via dei Fori Imperiali and see the dramatic background of Piazza Venezia. We will take a first look at Caesar's Forum of which a few shops and an elegant pink marble portico remain, in addition to the magnificent temple constructed by orders of Caesar in honour of Venus, as he had sworn to the Goddess, progenitor of his people, before the battle of Farsaglia.