Fort Worth sits on a blend of timber and prairie land that is transected by the Trinity River and its tributaries. These physical attributes invited the creation of parks to preserve scenic landscapes and to provide Fort Worth residents with access to nature. Generous land donations as well as the foresight of city leaders allowed for the acquisition of park land, particularly after the formation of the park department in 1909. Local architects and such well-known names as George E. Kessler, Hare and Hare, Philip Johnson, and Lawrence Halprin have left a rich legacy of nationally recognized parks and recreational amenities. These include the Fort Worth Zoo, Fort Worth Botanic Garden, the Water Gardens, Heritage Plaza, Fort Worth Nature Center and Refuge, and Fort Woof, the city's first dog park.