At the 2010 meeting of the Near Eastern Archaeological Society, James Charlesworth gave a brief report on the two pools mentioned in the gospel of John, the pool of Bethesda (Bethzatha, John 5:2) and the Pool of Siloam (John 9:7). Because these two pools were unknown until recently, scholarship has occasionally dismissed John’s Gospel as non-historical. For example, since Bethesda was said to have five “roofed colonnades,” medieval commentaries took this as an allegory for the five books of the Law. In fact, there were two connected pools with a shared colonnade between them, hence five in all.
Siloam was thought to be the pool at the end of Hezekiah’s tunnel, but it is now virtually certain that a nearby pool was the pool of Siloam.
Charlesworth cited Ronny Reich as claiming both pools were mikvoth, pools used for ceremonial cleansing before going up to the Temple. In both cases there are stairs leading to a platform, which is consistent with other mikvoth around Jerusalem. What is missing is the divider found on most of these pools. Charlesworth indicated that there were other mikvoth which did not have the divider, even though it is a common feature. Charlesworth speculated that the pool was a reservoir which was re-configured during the Herodian period to serve as a mikveh.
If these identifications are correct, then the pool of Siloam was a massive mikvoth at the southern approach to the Temple mount. The pool is fed by the Gihon spring (providing living water) and could have serviced the thousands of pilgrims which came to Jerusalem during the feast days. That Jesus would heal a man and send him to a mikvah is significant. The blind man is healed, ritually cleansed, and then he goes up to the Temple to worship.
The pool of Bethesda was likely another water reserve re-configured as a mikvah. The pool may have been built by Simeon, a high priest who lived about 200 B.C. (Sirach 50:3). Charlesworth showed several snake figures excavated at the pool, indicating that the area also housed an Asclepeion, a pool dedicated to the healing god Asclepius. It is possible then the blind, lame, and paralyzed were not waiting for the God of Israel to heal them, but rather the god Asclepius. If this is true, then there is a tension in the story: who are you going to believe can heal you, the god Asclepius, or the God, Jesus?
In both cases, the identity of these pools help to illuminate the stories as they appear in John. The writer of John is not simply familiar with major features of Jerusalem, these locations are critically important to the point of these two healings.