China’s first emperor died in 210 BC, but thousands of terracotta soldiers and traps were placed to guard his tomb.

While large parts of the necropolis surrounding the mausoleum have been explored, the emperor’s tomb itself has never been opened despite the huge amount of intrigue that surrounds it. Eyes have perhaps not peered inside this tomb for over 2,000 years, when the feared emperor was sealed inside.

A prime reason behind this hesitancy is that archaeologists are concerned about how the excavation might damage the tomb, losing vital historical information. Currently, only invasive archaeological techniques could be used to enter the tomb, running a high risk of causing irreparable damage.

In an account written by ancient Chinese historian Sima Qian around 100 years after Qin Shi Huang’s death, he explains that the tomb is hooked up to booby traps that were designed to kill any intruder.