Grutas Xoxafi, Cave system in Santiago de Anaya, Mexico

Grutas Xoxafi is a cave system on Cerro Teptha in the ejido El Palmar, Santiago de Anaya, Hidalgo. Its two tunnels were carved by water through limestone over 250 million years. The first descends 80 m over 600 m and allows rappelling to 100 m; the second has a 45 m rappel. Walls, ceilings and stalactites are coated in "leopard skin", a texture of ferrous oxide and saltpetre.

The cave developed over millions of years through water erosion that carved out a complex network of underground passages and chambers. This slow geological process shaped the formations visible in the site today.

Xoxafi is an Otomi word meaning "thunder that falls", not lightning. The name comes from the Otomi language spoken in the Mezquital Valley around Santiago de Anaya. Local residents, the state government and the municipality jointly run ecotourism visits and give talks on the bats without disturbing them, with support from the Programa para la Conservación de los Murciélagos de México.

Wear sturdy shoes with good grip since the cave floor is uneven and can be slippery in places. Bring a flashlight or headlamp even though the site has some lighting, as it helps navigate darker sections better.

The cave's name comes from Otomi for "thunder that falls." Inside, a natural texture called "leopard skin" coats walls, ceilings and stalactites, formed by ferrous oxide and saltpeter. Some areas hold rock paintings, and the cave shelters about 100,000 bats of six species, three endangered.