Calixtlahuaca is an Aztec-period archaeological site on the northern edge of Toluca, the former capital of the Matlatzinca people who occupied the Toluca Valley before being conquered by the Aztecs in the 15th century. The most striking structure is the circular temple of Ehecatl-Quetzalcoatl, dedicated to the wind god — round temples are unusual in Mesoamerica and this is one of the best preserved.
The site is small and quiet, with grass between the stone platforms and a small site museum. Allow an hour. A taxi from central Toluca takes about 20 minutes.