Explanation:

• The International Day for Monuments and Sites (World Heritage Day) is observed on 18 April each year to promote awareness about the diversity of cultural heritage of humanity, their vulnerability and the efforts required for their protection and conservation.
• The International Day for Monuments and Sites was proposed by the International Council on Monuments and Sites (ICOMOS) on 18 April 1982 and approved by the General Assembly of UNESCO in 1983.