Vesta was the Roman goddess of the hearth. The Vestal cult was an important and elite Roman cult.
The Vestal Virgins, the priestesses of Vesta, were chosen at the age of six to ten. They were selected by the emperor in his role as the Pontifex Maximus, the chief religious authority of the State. The main duties of the Vestals were to guard the sacred eternal flame in the temple and to follow the vow of chastity. The sacred flame stood for the eternity of Rome. It was believed that if the fire extinguished Rome would fall.
Because of their important duties, the Vestals belonged to the most powerful women in Rome. They were allowed to own land, they had the right to pardon prisoners, and nobody was allowed to injure a Vestal Virgin.
They served for 30 years - 10 years for studying, 10 years for following their duties, 10 years for teaching new priestesses. If a Vestal Virgin broke the vow of chastity she was buried alive!
Architecture & Art
The circular Temple of Vesta got its ancient Greek style probably around the 3rd century BC. It was rebuilt multiple times. Some of the Corinthian columns are still standing. Originally, it was 20 columns in total.
It is believed that the round form of the temple might trace back to the form of early huts of Roman colonies. Maybe, such a hut was an early location for Vestal cult.
Inside the temple, there was the hearth for the sacred flame guarded by the Vestal Virgins. It also stored the legal wills of the Senators. And it housed the Palladium, a statue of Greek Athena, the protectress of cities (Roman Minerva).
Especially during summer, it can get quite hot. Since you can hardly find any shadow it is a good advice to visit the Roman Forum in the morning hours. And bring comfortable shoes because the ground is a bit rough.
I also advise you to book tickets online. Usually, the tickets are sold as combi tickets that also allow access to the Colosseum and Palatine Hill.
Last but not least, you shouldn't miss the view from the top of Palatine Hill. From there, you can nicely overlook the whole Roman Forum.