Page "Vesta (mythology)" Paragraph 10

Dumézil elaborates that in Rome the whole site of the city itself was considered as an extended sacrificial ground, with the temple of Vesta performing the function of hearth of the landlord and other temples that of sacrificial fires.

He remarks that the temple of Vesta was the only ancient temple in Rome to be built in a round shape and covered with a dome to protect the sacred fire from rain, other temples being quadrangular.

Ancient Romans as well as other Indoeuropean people believed Earth is a sphere.

Every temple however had to have two fires of which one was a hearth ( Latin focus ), representative of the fire ( Latin foculus ) of Vesta as the hearth of the city, and the main was the sacrificial ara.