One of Lake Forest's most notable features is its virgin prairies and other nature preserves. In 1967, a group of 12 long-time residents of Lake Forest formed a land conservation organization, Lake Forest Open Lands Association. Its express purpose was to purchase or otherwise set aside the rapidly disappearing open spaces in the city, in the interests of preserving animal habitat, restoring ecosystems, and providing environmental education for the city's children. In the next 38 years, the group managed to acquire more than within the city limits, which now form six nature preserves with of walking trails open to the public.