Calixtlahua is a short drive from Mexico City (at least if you live on the west side of the city) very close to Toluca. It's also a lovely drive, especially in the summer.
As usual, I was able to get us very close to the site, but we had to ask for directions to the pyramid at the end. There have been very few sites here that we haven't needed Spanish to get to. Google maps has managed to get us to a couple and two had really good signs.
There are four different sections at this site and you'll do some climbing. This is one of our favorites.