The Hasmoneans built an open air aqueduct to bring water from the north side of the Temple Mount into the city and the Temple Mount. The water was collected in the Struthion pool. Herod later cut through the aqueduct and converted the water supply into a moat and water reservoir around Fort Antonia. He continued to use the aqueduct to fill this pool, cutting off the supply of water to the city and the Temple Mount from this location. Josephus describes this reservoir and calls it Struthius (“sparrow” or “lark”). It was one of the smaller reservoirs in Jerusalem.

After Hadrian took the city in 135 he covered it with an arched roof to create water cisterns below, and then built a marketplace above. Hadrian’s arches split the pool into two halves. The pool was eventually forgotten until the Convent of the Sisters of Zion was built on this location in the 1800’s, and the pools were exposed. Today the Struthion Pool still collects water and can be seen at the north end of the Western Wall Tunnels.