World's largest Buddhist monument, 9th-century Mahayana stupa on Java. Inscribed 1991.
From Wikipedia
Borobudur Temple Compounds is the World Heritage designation of the area of three Buddhist temples in Central Java, Indonesia. It comprises Borobudur, Mendut, and Pawon. The temples were built during the Shailendra dynasty around the 8th and 9th centuries CE and fall on a straight line.