Artis is the name by which the Koninklijk Zoölogisch Genootschap Natura Artis Magistra is more commonly known, which has been based in Amsterdam since 1 May 1838. The Artis has an area of 14 hectares and is divided into various sectors: in addition to the large zoological garden, there is an Aquarium, the Amphibiarium, the Planetarium, the Zoölogisch Museum, the Geologisch Museum, and an entomological museum. Overall, the structure houses about 8,200 animals, of 786 different species. Artis welcomes an average of one million visitors a year.