Valley of Rephaim

Concise Bible Dictionary:

A valley on the south of Jerusalem, in which the Philistines gathered themselves against Israel, and where David twice signally defeated them (2 Sam. 5:18, 2218The Philistines also came and spread themselves in the valley of Rephaim. (2 Samuel 5:18)
22And the Philistines came up yet again, and spread themselves in the valley of Rephaim. (2 Samuel 5:22); 2 Sam. 23:1313And three of the thirty chief went down, and came to David in the harvest time unto the cave of Adullam: and the troop of the Philistines pitched in the valley of Rephaim. (2 Samuel 23:13); 1 Chron. 11:1515Now three of the thirty captains went down to the rock to David, into the cave of Adullam; and the host of the Philistines encamped in the valley of Rephaim. (1 Chronicles 11:15); 1 Chron. 14:9-179And the Philistines came and spread themselves in the valley of Rephaim. 10And David inquired of God, saying, Shall I go up against the Philistines? and wilt thou deliver them into mine hand? And the Lord said unto him, Go up; for I will deliver them into thine hand. 11So they came up to Baal-perazim; and David smote them there. Then David said, God hath broken in upon mine enemies by mine hand like the breaking forth of waters: therefore they called the name of that place Baal-perazim. 12And when they had left their gods there, David gave a commandment, and they were burned with fire. 13And the Philistines yet again spread themselves abroad in the valley. 14Therefore David inquired again of God; and God said unto him, Go not up after them; turn away from them, and come upon them over against the mulberry trees. 15And it shall be, when thou shalt hear a sound of going in the tops of the mulberry trees, that then thou shalt go out to battle: for God is gone forth before thee to smite the host of the Philistines. 16David therefore did as God commanded him: and they smote the host of the Philistines from Gibeon even to Gazer. 17And the fame of David went out into all lands; and the Lord brought the fear of him upon all nations. (1 Chronicles 14:9‑17); Isa. 17:55And it shall be as when the harvestman gathereth the corn, and reapeth the ears with his arm; and it shall be as he that gathereth ears in the valley of Rephaim. (Isaiah 17:5)). In the AV it is twice called the “VALLEY OF THE GIANTS” (Josh. 15:88And the border went up by the valley of the son of Hinnom unto the south side of the Jebusite; the same is Jerusalem: and the border went up to the top of the mountain that lieth before the valley of Hinnom westward, which is at the end of the valley of the giants northward: (Joshua 15:8); Josh. 18:1616And the border came down to the end of the mountain that lieth before the valley of the son of Hinnom, and which is in the valley of the giants on the north, and descended to the valley of Hinnom, to the side of Jebusi on the south, and descended to En-rogel, (Joshua 18:16)). Identified with el Bukeia, 31° 45' N, 35° 13' E.
Plain of Rephaim from Jaffa Gate.