The World Heritage Day is an international observance held on 18 April.

The International Day for Monuments and Sites also known as World Heritage Day is an international observance held on 18 April each year around the world with different types of activities, including visits to monuments and heritage sites, conferences, round tables and newspaper articles. Each year has a theme, for example sustainable tourism in 2017.

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. The aim is to promote awareness about the diversity of cultural heritage of humanity, their vulnerability and the efforts required for their protection and conservation.