What is the difference between a national park and a UNESCO World Heritage Site?
Who designates it and what the designation does. A national park is a national protected area with legal planning powers; a World Heritage Site is an international recognition with no direct legal authority of its own.
National parks. Designated by a country under its own legislation, and what that means varies enormously between countries — which is the source of most confusion.
In the United States, national parks are largely federally owned land, with restricted development and few permanent residents.
In England and Wales, national parks are lived-in working landscapes. Most land is privately owned, there are towns, farms and businesses inside them, and the park authority is a planning authority with statutory purposes — conserving natural beauty and cultural heritage, and promoting understanding and enjoyment — plus a duty to foster the economic and social wellbeing of local communities. Being in a national park does not mean the public may go anywhere, which surprises visitors: access rights depend on separate legislation, rights of way and open access land designations.
World Heritage Sites. Inscribed by UNESCO under the World Heritage Convention, for outstanding universal value — cultural, natural or mixed. The list includes buildings, cities, landscapes and natural areas.
What inscription actually does. It is recognition, not protection. UNESCO has no power to prevent development; protection depends entirely on the national and local law already applying. What inscription brings is international attention, obligations on the state to manage and report, technical support, and a form of leverage — the possibility of being placed on the List of World Heritage in Danger, or delisted.
Delisting is rare and consequential. It has happened a small number of times, including where development was judged to have destroyed the value for which a site was inscribed — Dresden's Elbe Valley over a bridge, and Liverpool's waterfront over dockside development.
Other designations frequently confused: Areas of Outstanding Natural Beauty (now National Landscapes in England and Wales), Sites of Special Scientific Interest, Biosphere Reserves, Ramsar wetland sites, and Geoparks — each with different criteria and different legal force.
Tourism effects are double-edged: designation raises visitor numbers, which funds conservation and threatens the thing designated.