An officially designated area of open countryside encircling a town or city in which development is severely restricted is called a greenbelt. Greenbelts have four important functions: to prevent the unrestricted sprawl of large built-up areas; to provide areas of unspoiled countryside where people can find recreation and enjoyment; to provide habitat for some plant and animal species; and to provide for the continued use of farmland, woodland, or common land. In Boise, Idaho, the Boise River Greenbelt illustrates how transformative greenbelts can be. Up until the 1960s the river area was dumping ground for trash, industrial waste, and raw sewage; today twenty-two miles of greenbelt through the city provide towering trees and abundant wildlife.

Arthur Sze