Lisse, the Netherlands - April 22, 2011: People visiting flower park Keukenhof in the Netherlands. Focus is on a senior man in a wheelchair being pushed by a woman. At the background are other visitors. Keukenhof is the worlds largest flower park, covering an area of 32 hectares and exposing around 7 million flowers. It is visited yearly by around 800,000 visitors. The park is open between the last week of March and mid-May.