Immediately after the Temple of Caesar, the religious area of the Forum begins with the Regia and Temple of Vesta. The Regia was originally the residence of Numa Pompilius, the Second King of Rome, but it later became the place where the highest religious authorities carried out their function

The building housed a shrine to Mars and was the place where the Pontifex Maximus, the High Priest, kept the archives, the calendar and the annuals of Rome. You can see just a few columns remaining of the small circular Temple of Vesta, one of the oldest and most important holy places of Rome. This was the ancestral hearth of the Roman Nation, the place where the objects that Aeneas had bought from Troy were kept, and the temple that was guarded by the Vestal Virgins, the only female priesthood in Rome.
These six maidens were the King's daughters during the archaic era, but were later chosen from among the daughters of noble families. They entered the temple at the age of 6 and, with a vow of virginity, remained a priestess for 30 years. If the vow was broken, the Vestal was buried alive and the man was flogged to death in front of the Curia.
In exchange for the rigid rules that governed their lives, the Vestal Virgins enjoyed semi-divine status and many privileges: they were not responsible to their fathers' control but answered to the Pontifex Maximus alone, they had financial security and prestige, they traveled about the city in a carriage, they had reserved seats at shows and performances, they took part in all public ceremonies and they could be buried inside the city walls.
You can still see the house of the Vestal Virgins just behind the Temple. This was abandoned only after 394 AD when the Emperor Theodosius abolished the pagan religion. It was then occupied by officials of the Imperial Court and later by those of the Papal Court.