This was the second festival in the year dedicated to the three most important deities in the Roman pantheon. Jupiter the Sky God, God of Justice, God of Rome. His wife and sister, ‘Queen’ Juno protector of women. Minerva, Daughter of Jupiter. Goddess of Wisdom and Craft.
The main Temple was in Rome on the Capitoline Hill known as aedes Iovis Optimi Maximi Capitolini (“Temple of Jupiter Best and Greatest on the Capitoline”). Similar temples spread throughout the Roman world, normally with a triple cella (inner sanctum) to allow separation of worship.
In London a temple was discovered to the west of the first Forum (built AD 75). There is no clue as to its dedication but the Capitoline Cult has been suggested as well as for the Cult of the Emperor.