Look at the surrounding rock rising above the head. It is easy to spot that we are inside an artificial cave created due to stone quarrying. Jerusalem was built of stone. Often, the stone was hewn right in the city area, and the spaces created were used to store rainwater. If you look up the ceiling, you can see that it is arched with dressed stones with several windows in between. The top of the reservoir has openings for buckets that were dropped down with ropes to carry water. Tradition says that here they discovered the cross on which Jesus was crucified. Like many other objects associated with the death and resurrection of Jesus, the cross carried miraculous virtues. The cross was called the giver of life. The Crusaders held the cross with them in the battle against Saladin in Karni Hittin. The Crusaders lost this battle and lost the Holy Land. The cross was lost forever.