Situated at the foot of Capitol Hill, this lush conservatory serves as the nation's living plant museum. The first greenhouse was established in 1842 to conserve the collection of exotic specimens brought from the South Seas by a team of US explorers. The garden features a skillful blend of two building types traditionally used for storing and displaying plants: the 19C iron and glass greenhouse and the stone orangerie of French palace gardens, with full-length arched windows