Photo: Venus Glyph
April 18 is World Heritage Day, aka International Monuments and Sites Day, celebrating the work of the International Council on Monuments and Sites (ICOMOS) — http://www.icomos.org. There are events around the world.
On April 18, 1982 on the occasion of a symposium organized by ICOMOS in Tunisia, the holding of the “International Day for Monuments and Sites” to be celebrated simultaneously throughout the world was accepted by the UNESCO General Conference who passed a resolution at its 22nd session in November 1983 recommending that every April 18 be declared “International Monuments and Sites Day”. This has been traditionally called the World Heritage Day.
Keep track of official events on the ICOMOS calendar:
World Heritage Day