Before the Spanish arrived, a labyrinth of catacombs was built here; the first Spaniards called it La Ciudad Perforada (the perforated city). Archaeologists understand little of the tunnels, which are off-limits to visitors.
Conquistador Pedro de Alvarado arrived in 1522 but was driven back by the Chichimecs. A small garrison was founded here in 1575 to protect Zacatecas−Mexico City silver convoys. Eventually, as the Chichimecs were pacified, the region’s hot springs sparked the growth of a town; a large tank beside the Ojo Caliente springs helped irrigate local farms that fed hungry mining districts nearby.
Today, the city’s industries include textiles, wine, brandy, leather, preserved fruits and car manufacturing.