Dholavira is a relatively recent discovery. This Indus city has been excavated by the Archaeological Survey of India since 1989. Habitation at the site began well before 3000 B.C. and continued for more than a millennium. This long history provides important information about the formative stage of the Indus Civilization and its subsequent decline. The city's unique stone architecture is partly responsible for the remarkable preservation of its "Citadel", "Middle Town" and "Lower Town," all surrounded by gigantic water reservoirs that were cut into the bedrock. Application is currently being made to UNESCO to register and protect Dholavira as a World Heritage site.