Valley of Jehoshaphat

Concise Bible Dictionary:

This is mentioned only in Joel 3:2,12²I will also gather all nations, and will bring them down into the valley of Jehoshaphat, and will plead with them there for my people and for my heritage Israel, whom they have scattered among the nations, and parted my land. (Joel 3:2)
¹²Let the heathen be wakened, and come up to the valley of Jehoshaphat: for there will I sit to judge all the heathen round about. (Joel 3:12), as a place where the nations will be judged for their treatment of God’s people, when Judah is being brought into blessing. The name signifies “Jehovah is judge,” and some think that it is used symbolically for the place where God will judge. In Joel 3:14¹⁴Multitudes, multitudes in the valley of decision: for the day of the Lord is near in the valley of decision. (Joel 3:14) occurs “the valley of decision,” which is also connected with God’s judgments.

Others however associate the above with the valley lying between Jerusalem and the Mount of Olives, now called the Valley of Jehoshaphat; but no trace of this name as attached to that particular valley can be found earlier than the fourth century. It was and is otherwise known as the Valley of the KIDRON.