Orange trees lining one of the indoor cloisters at the Cloisters, Fort Tryon Park, New York.
The Crystal Cave of Giants, about 1000 feet below the surface in the Naica Mine, Chihuahua, Mexico, where lead, zinc, and silver are mined. The host rock is limestone, and the crystals are selenite (gypsum). See figure at left for scale.
More information: http://www.crystalinks.com/mexicocrystals.html