Mapimí Biosphere Reserve (Zone of Silence)

A Chihuahuan Desert reserve shared between Chihuahua, Coahuila, and Durango protecting the Bolsón de Mapimí ancient lakebeds, home to the endemic bolson tortoise — one of the largest terrestrial tortoises in North America — and to the remarkable flora of the Chihuahuan desert that contains 20% of the world's cactus species. The local legend of a "Zone of Silence" where radio signals fail, created by a 1970 US rocket crash, has made the reserve famous in Mexican popular culture.