The pool of Siloam was originally made by King Hezekiah, who ruled the Kingdom of Judah from 715 to 686 B.C. (2Chronciles 32:30). It was constructed so that the city of Jerusalem, naturally deficient in water, would be better able to survive a siege.
The Biblical pool of Siloam was discovered in Autumn 2004 when workers, digging for a new sewer line, uncovered several stone steps. Archaeologists were immediately notified when the steps were found. Subsequent excavations confirmed the authenticity of the location. Before this discovery it was believed that a Byzantine reconstruction, less than 70 yards away, was the pool mentioned in the Gospel of John.
Siloam's pool is located on the southern slope of the city of David (the original site of Jerusalem) and is just outside the walls of the Old City. It was fed by the waters of the Gihon springs, which were carried to it by two aqueducts. The related tower, mentioned only in the book of Luke (Luke 13:4), is believed to have been part of the city wall near the waters.
Water from the pool, combined with the ashes of a red heifer, was used by temple priests to perform a unique cleansing ceremony (Numbers 19). According to Jewish tradition, the water was retrieved for the religious rite by children riding bulls.
It was at the Pool that Jesus healed a man who was blind from birth.
6. After saying these things, He spat on the ground, and made clay of the spittle, and applied the clay to the eyes of the blind man. 7. And He said to him, "Go and wash in the pool of Siloam" (which is, by interpretation, "Sent") (John 9)
After the man washed in the pool he received his sight.
Tradition states that on the eighth day of the Feast of Tabernacles (known as the Last Great Day), a golden vessel was filled with water from Siloam and taken to the temple. When the water reached the altar it was poured out before God with much rejoicing. Jesus referred to this tradition when he stated, on the Last Great Day, that from those who have God's spirit would come 'rivers of living water' (John 7:37 - 38).