This is one of the earliest botanic gardens in Europe, made to teach medical students about medicinal plants. Europe's first potato was grown here in 1590. Goethe, the German poet visited the garden in 1786, planted a palm tree and anticipated the theory of evolution. The garden is protected by a great circular wall, rebuilt during the eighteenth century, with statues and busts. The circular wall encloses four square gardens, two of which have circles within. This geometry parallels Andrea Palladio's use of circles and squares to symbolise perfection. Palladio was born in Padua and was 37 years old when the Orto Botanico was founded, in 1545. It is likely that the designer of the Orto Botanico, like Palladio, was inspired by an enthusiasm for Platonic philosophy.