Inside the Palm House at Kew Gardens, London

Under the central dome of Kew's Palm House, palms and cycads reach for the white-painted ribs while a raised walkway circles overhead. The house is kept hot and humid for rainforest plants, and among them is a South African cycad, Encephalartos altensteinii, that Kew's collector Francis Masson brought back in 1775 and that moved into the Palm House when it opened. It is widely called the oldest pot plant in the world. Climb the spiral stairs to the gallery for the view down into the canopy.