The world's first botanical garden was created in Padua in 1545. It still preserves its original layout – a circular central plot, symbolizing the world, surrounded by a ring of water. Other elements were added later, some architectural (ornamental entrances and balustrades) and some practical (pumping installations and greenhouses). It continues to serve its original purpose as a centre for scientific research.

: World Heritage Convention
http://whc.unesco.org/en/list/824