unesco

These are UNESCO World Heritage Sites, Biosphere reserves, Geopark or other related entity that I've visited.

A World Heritage Site is a landmark or area with legal protection by an international convention administered by the UNESCO. World Heritage Sites are designated by UNESCO for having cultural, historical, scientific or other forms of significance. The sites are judged to contain "cultural and natural heritage around the world considered to be of outstanding value to humanity". -- Wikipedia, World Heritage Site