Temple of Castor and Pollux
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The Temple of Castor and Pollux was originally built around 484 B.C., after the battle of Lake Regilus, because before the battle, the Roman dictator Postumius had vowed to build a temple to them if Rome was victorious. As legend says, Castor and Pollux, the twin sons of Jupiter, appeared on the battlefield to help the Romans, and once again after the battle had been won in the Roman Forum, this time announcing the victory. The temple stands on the supposed spot of their appearance.