Ujung Kulon is believed to sustain the last viable natural population of this species, estimated at approximately 60 individuals. It is also home to three endemic primate species; the Javan gibbon, Javan leaf monkey and silvered leaf monkey. The property includes the Ujung Kulon peninsula and several offshore islands that demonstate on-going evolutionary processes, especially following the dramatic Krakatau eruption in 1883. The mainland component of the property was established as a nature reserve in 1967 and the Ujung Kulon reserve complex was declared a ‘proposed’ national park in 1980 with the Krakatau Nature Reserve included into the site in 1983. The long term management plan of Ujung Kulon National Park (2001-2020) is the basis for maintaining its natural beauty and preserving the critical habitats.