A short walk west of the Retiro, adjacent to the Museo Nacional del Prado, the garden celebrated its 250th anniversary in 2005. However, the garden hasn't always been in this location. Founded in the 18th century by Fernando VI at the Huerto de Migas Calientes, it was subsequently moved to its present location by Carlos III. Today it contains more than 104 species of trees and 30,000 types of plants. Also on the premises are an exhibition hall and a library specializing in botany.