It took 720,000 workers and nearly 40 years to build the mausoleum. The last workers and their supervisors were buried alive along with the dead emperor, taking the secret of its construction to their graves. Designated a World Heritage Site by UNESCO in December 1987, the mausoleum of the First Qin Emperor, better known as the site of the terracotta warriors, is the largest underground tomb in the world, and has kept its secrets safe for over 2,000 years.

Emperor Qin Shihuang and his mausoleum

Emperor Qin Shihuang [Photo from itl.gov.cn]