Teotihuacan - first and foremost, this is one heck of an archeological site. While marveling at the sheer scale, I missed paying attention to about half of what our guide was explaining. And almost died climbing half way up the steps of the Temple of the Moon (they don’t let you climb all the way to the top).
Driving to and from Teotihuacan gives one a sense of the vastness of Mexico City and the surrounding environs.
While the days are sunny and hot, the breeze kicks up in the late afternoon and clouds usually move in.