This small archaeological site is 1km northeast of the center. There are actually two pyramids, one inside the other. You can climb on the outer base and see the older pyramid within, with a double staircase leading up to the remains of a pair of temples. Tlahuicas built the older pyramid over 800 years ago; the outside one was being constructed by the Aztecs when Cortés arrived, and was never completed. The name Teopanzolco means ‘Place of the Old Temple'.