2 Kings 23:6, 12, 15

He removed the Asherah idol from the Temple of the LORD and took it outside Jerusalem to the Kidron Valley, where he burned it and beat it into dust. Then he threw the dust on the graves of the common people.

The kings of Judah had built altars on the roof of the upstairs room of Ahaz. Josiah broke down these altars and the altars Manasseh had made in the two courtyards of the Temple of the LORD. Josiah smashed them to pieces and threw their dust into the Kidron Valley.

Josiah also broke down the altar at Bethel—the place of worship made by Jeroboam son of Nebat, who had led Israel to sin. Josiah burned that place, broke the stones of the altar into pieces, then beat them into dust. He also burned the Asherah idol.