The sanctuary, which lay between today's "piazza della Pilotta" and the large square facing Quirinal Palace, was built by Caracalla on the western slopes of the hill, covering over , as its sides measured . It was composed by a long courtyard (surrounded by a colonnade) and by the ritual area, where statues and obelisks had been erected. Designed to impress its visitors, the temple boasted columns tall and in diameter, visually sitting atop a marble stairway that connected the base of the hill to the sanctuary.