If you were disappointed by not being able to climb the 3 pyramids at Teotihuacán, then you will love climbing around here. This massive temple complex on a hill south of Mexico City may have been built as a successor to the more famous site north, as it has similar art. It also suffered a similar fate, as it was burned around 900. When you work your way around to the top of the Great Pyramid above, there are various animal symbols, a large plaza with baths, and even an observatory. Before telescopes, measurements and observations were taken through a tube in the ceiling by recording where the light shone on different days of the year. Be sure to get a good look at the temple of the feathered serpents. The head priest had a residence above the great temple, and the views of the valley are magnificent! The whole drive from Puebla was enjoyable, as I skirted around past the smoking volcano Popocatépetl.