Desert Garden Conservatory, The Huntington

Opened in 1985 within the renowned Huntington Desert Garden in San Marino, this conservation greenhouse holds more than 2,200 specimens representing 1,261 species and subspecies across 43 botanical families. It serves as a genetic reserve and research center, and runs the International Succulent Introductions program, which distributes up to 40 new succulent varieties to other institutions each year. Unlike the outdoor garden, which spans nearly 4 hectares in the open air, the conservatory allows the most fragile or endangered species to be grown under cover. It rounds out one of the most highly regarded cactus and succulent collections in the world.