It was a pool in Jerusalem. Jesus healed a blind man's eyes here.
John 9:1As he went along, he saw a man blind from birth.John 9:2His disciples asked him, “Rabbi, who sinned, this man or his parents, that he was born blind?”John 9:3“Neither this man nor his parents sinned,” said Jesus, “but this happened so that the works of God might be displayed in him.John 9:4As long as it is day, we must do the works of him who sent me. Night is coming, when no one can work.John 9:5While I am in the world, I am the light of the world.”John 9:6After saying this, he spit on the ground, made some mud with the saliva, and put it on the man’s eyes.John 9:7“Go,” he told him, “wash in the Pool of Siloam” (this word means “Sent”). So the man went and washed, and came home seeing.
There was a tower here that collapsed in an accident.