Dictionary.com defines a park as: 1.an area of land, usually in a largely natural state, for the enjoyment of the public, having facilities for rest and recreation, often owned, set apart, and managed by a city, state, or nation. 2. an enclosed area or a stadium used for sports: a baseball park. 3.a considerable extent of land forming the grounds of a country house. 4.British . a tract of land reserved for wild animals; game preserve. 5. Western U.S. a broad valley in a mountainous region.
The Oxford on-line says: 1. A large public garden or area of land used for recreation 1.1 A large enclosed piece of ground attached to a country house 1.2 A large enclosed area of land used to accommodate wild animals in captivity