The three columns are what remains of the Temple of Castor and Pollux. The original temple was built in honor of the gods Castor and Pollux who were believed to have helped the Romans win a battle against the Etruscans in 496 B.C. These columns are the remains of the temple that replaced the original temple, which was destroyed in a fire in 14 B.C. This temple was completed in 6 A.D. Most of the original marble was stolen following the fall of Rome to be used in churches and other public buildings.