File photo of the Terracotta Army Pit 1.
There are four main pits associated with the terracotta army.
These pits are located about 1.5 km east of the burial mound and are about 7 metres deep. The army is placed as if to protect the tomb from the east, where all the Qin Emperor's conquered states lay. Pit one, which is 230 metres long and 62 metres wide, contains the main army of more than 6,000 figures.
Pit one has 11 corridors, most of which are over 3 metres wide, and paved with small bricks with a wooden ceiling supported by large beams and posts. This design was also used for the tombs of noblemen and would have resembled palace hallways. The wooden ceilings were covered with reed mats and layers of clay for waterproofing, and then mounded with more soil making them, when built, about 2 to 3 metres higher than ground level.
Pit two has cavalry and infantry units as well as war chariots and is thought to represent a military guard. Pit three is the command post, with high ranking officers and a war chariot. Pit four is empty, seemingly left unfinished by its builders.
Some of the figures in pit one and two showed fire damage and remains of burnt ceiling rafters have also been found; these, together with the missing weapons, have been taken as evidence of the reported looting by Xiang Yu and its subsequent burning. The burning is thought to cause the collapse of the roof which crushed the army figures below, and the terracotta figures presently displayed have been reconstructed from fragments of the crushed figures.
A large number of other pits which formed the necropolis have also been excavated.
These pits may lie within or outside the walls surrounding the tomb mound. These accessory pits variously contain bronze carriages, terracotta figures of entertainers such as acrobats and strongmen, officials, stone armour suits, burials sites of horses, rare animals, and labourers, as well as bronze cranes and ducks in an underground park.