World Heritage sites are natural and cultural sites identified by UNESCO following the adoption, during the 1972 General Conference, of the “Convention Concerning the Protection of the World Cultural and Natural Heritage”. There are a total of 890 sites (689 cultural, 176 natural, and 25 mixed) currently inscribed on the World Heritage List. World Heritage sites are valuable and irreplaceable treasures of the world. Some sites are listed as endangered due to man-made or natural causes. UNESCO is bringing attention to the need for the restoration, conservation and preservation of World Heritage sites that are under threat. The calendar is published under: http://panasonic.net/UNESCO_worldheritage_calendar/en/may.html