Wimbledon Park was founded in the 18th century. It consists of 27 hectares of land, and features one of the largest lakes in south London.
There are many things to do in the park including taking your kids to the playgrounds (complete with a paddling pool (summer only)), feeding the ducks, and there are lots of tennis courts. You can go to the café or even bring your own bbq, and there is plenty of space to play football, cricket, frisbee, or fly a kite in the field.