This was the ancient temple of the Sun and Moon, and was built on the south side of the seating of the Circus Maximus. A statue of the Sun, most likely driving a chariot, topped this structure. Edgyptian obelisks were later added by Augustus and Constantius II to give honor to the Sun. For Romans, obelisks symbolized sunbeams. August 24th was the temple's festival day.
Picture: http://www.romereborn.virginia.edu/ge/TS-056.html
