Occupation of the city itself continued for approximately 4,000 years, from c. 2600 BC to the mid-14th century AD, when the forces of Timur massacred its population. The site is a World Heritage Site, having been added to that organisation's list of sites in danger in 2003 following the conflict that erupted following the US-led 2003 invasion of Iraq and as a result of a proposed dam which would flood some of the site. Assur lies south of the site of Nimrud and 100 km (60 mi) south of Nineveh.