Excavations here from 1936 to 1941 led to the discovery of the first hominid fossil at this site. Later, 50 fossils of Meganthropus palaeo and Pithecanthropus erectus/Homo erectus were found – half of all the world's known hominid fossils. Inhabited for the past one and a half million years, Sangiran is one of the key sites for the understanding of human evolution.

Źródło: World Heritage Convention
http://whc.unesco.org/en/list/593