Cañada de la Virgen is an intriguing pre-Hispanic pyramid complex and former ritual and ceremonial location, dating from around AD 300 and in use until around 1050. Bones, believed to be from sacrificial ceremonies, and remnants were discovered here. The most interesting aspects include the alignment of the main temple to the planets, and the design of the site, which reflects the surrounding landscape. Although not as physically impressive as some Mexican pyramids the site has its own special magic.
The site is around 25km southeast of San Miguel: possibly the easiest and most rewarding visit for non-Spanish speakers is to take a tour with Albert Coffee Archaeotours or Coyote Canyon Adventures. The guides include archaeologists and anthropologists who discuss the site's fascinating cultural and historical context. Expect to pay around US$50. However, it's perfectly possible to visit completely independently. A taxi to the ticket office from San Miguel will cost around M$300. A shuttle bus is the compulsory transportation for visitors at the site. It runs between the ticket office and the ruins (several kilometers away); these depart on the hour between 10am and 4pm. At busy times you might have to queue for a seat so take a good book to read while you wait! Wear sensible shoes as you'll be walking on cobbled surfaces and steep steps. Note that larger bags are not allowed into the site due to some recent theft of relics.