The temples of Castor and Pollux are located in the center of the ancient Roman Square. Although there are only three vertical pillars left in the temple today, what is striking in the square is that the exquisite carvings can still be seen at the top of the pillars. Castor and Pollux were two twins of Zeus. Gemini is the two brothers. The temple was built for the battle of Lake Regilos, and it is said that the brothers helped Rome win. The Romans built temples and even set up the Gemini Brothers'Day.