El Pinacate and Gran Desierto de Altar

Declared a reserve in 1993 and a UNESCO World Heritage Site in 2013, it combines a volcanic field of more than 400 cinder cones and enormous explosion craters (maars) with the highest active dunes in North America, in the neighbouring Gran Desierto de Altar. Its landscape proved so like the lunar surface that NASA used it in 1965 and 1966 to give the Apollo astronauts geological training before their missions to the Moon. It is also one of the last refuges of the Sonoran pronghorn, the most threatened subspecies of pronghorn on the continent, with barely a few hundred animals left.