Bir el-Arwah

In the Dome of the Rock in Jerusalem: The cavity beneath the rock, accessible by a staircase near the south entrance, is known as Bir el-Arwah, the Well of Souls. It is said that here the voices of the dead mingle with the falling waters of the lower rivers of paradise as they drop into eternity. Another legend says that the dead meet here twice a month to pray. In earlier days, those who prayed here after having walked around the rock were given a certificate entitling them admission to paradise; it was to be buried with them. http://www.sacred-destinations.com/israel/jerusalem-dome-of-the-rock.htm