Cráter Rincón de Parangueo

Rincón de Parangueo is the most striking of the Siete Luminarias, a group of extinct volcanic craters around Valle de Santiago that has been protected as a natural monument since 1997. These craters are maars, formed when rising magma hit groundwater and exploded, leaving wide, steep-walled hollows. Local legend says the seven craters mirror the stars of the Big Dipper, and the area is also known for stories of UFO sightings.

What makes Parangueo special is the way in. A pedestrian tunnel about 400 meters long cuts through the crater wall; it was dug by hand in the early 20th century, and local guides with flashlights lead visitors through, sometimes bent over where the ceiling is low. You come out into a crater more than a kilometer across with a white, salt-crusted floor.

Until the 1980s the crater held a permanent lake, but heavy pumping of groundwater in the valley drained it, as it did the lakes of other Luminarias. Today only a small pool remains in the center, often reddish, surrounded by white mineral flats. It is an eerie, beautiful place, and a reminder of how fragile the Bajío's water is.