The Temple of Jupiter Optimus Maximus, Rome. Image from the Capitoline Museum.
Archaeology has demonstrated occupancy of the Capitoline Hill since the 17th century BCE. The first construction of the Temple of Jupiter Optimus Maximus was in the second half of the 6th century BCE. It contained three inner chambers, the central one for Jupiter Optimus Maximus, the right for Juno Regina, and the left for Minerva. The temple had been built over a much older shrine of Terminus, god of boundaries, and therefore he continued to receive worship alongside Jupiter. Juventas, goddess of youth, had a shrine within the cella dedicated to Minerva.
Each year, a festival called the Ludi Romani was held in September to honor Jupiter, along with Juno and Minerva. It included a solemn procession, a chariot race, exhibitions of horsemanship, and performances of dramas.
The Hellenized Roman gods, marble relief from the Arch of Trajan at Beneventum (in southern Italy), AD 114–117. In the Greek anthropomorphic style, Jupiter stands in forefront with his staff and thunderbolt; to his right, Minerva with her helmet; to his left, Juno dressed as a priestess with cloak pulled over her head. Jupiter, Minerva, and Juno are called the Capitoline Triad. The great temple on Capitol Hill (to Jupiter Optimus Maximus) celebrated their cult. Behind the triad, left to right: Hercules (with his club), Bacchus (with vines in his hair), Ceres (with the torch), and Mercury (with winged helmet). The sculptural style goes back to the Athenian Parthenon.