A very large, totally man-made natural area south of the city - you can't really call it a park - its 935 hectares. The Bos was devised in 1900 or work really began in the 1930s as an unemployment project during the crisis years.
137 km of footpaths, 51km of cycle tracks, jogging routes and horse riding. You can rent a boat on the lake, see open air theatre in the summer and it is one of the few places you can sledge if it every snows. Good for picnics in the summer - you can usually find a quiet place.
The Bosbaan rowing lake is the oldest manmade rowing course in the world. It was built in 1936 and has been twice widened since then.