Botanical Garden of Padua, UNESCO World Heritage since 1997, was founded in 1545 and is the oldest university botanical garden in the world still located in its original location. Born for the cultivation of medicinal plants as a "Garden of Simple", today's structure retains substantially that of initial project, work by Daniele Barbaro: a square inscribed in a circle that refers to ideal of Hortus Conclusus, heavenly place to house those seeking the relationship between man and the universe. Currently has an area of nearly 22,000 square meters and contains over 6,000 plants grown well representative of plant kingdom. There are some striking plants for their longevity, commonly referred to as "historic trees", first of all the so-called "Goethe's Palma", since German poet after having admired formulated his evolutionary insight in the "Essay on the Metamorphosis of Plants" , planting in 1585 and still the oldest in Garden. In 2014 it was inaugurated new wing called "Garden of Biodiversity".