In the Jewish tradition, it is the Jerusalem part of Kidron that is especially relevant.
The Tanakh mentions it as a site of idolatry and sacrifice to pagan deities.
It especially highlights a small westward offshoot of Kidron, called the Valley of Hinnom (Gehenna).
In the Kidron valley itself, according to Tanakhical texts, once stood the altars of pagan gods.
But they were burned, and their ashes were scattered over Kidron in the first temple period, in the reign of Asa and Yoshiyahu.
This valley might be considered the site of the very first Jerusalem founded by King David.
The nucleus of the future huge city stood practically at this "crossroads", where Hinnom comes out of Kidron to the West, by the Gihon Spring, still existing today and from time immemorial associated with important rituals described in the Tanakh.
As early as the eighth century B.C., under King Hizkiyahu, the famous water duct from Gihon to Jerusalem was laid, the one that is mentioned in theTanakh (Divrei Hayamim II; 32:30):
"It was Hezekiah who blocked the upper outlet of the Gihon spring and channeled the water down to the west side of the City of David".
Closer to our times, this water duct was discovered by the British archaeologist Charles Warren.