Smith's Bible Dictionary
the Valley Of Rephaim(1 Samuel 5:18,22; 23:13; 1 Chronicles 11:15; 14:9; Isaiah 17:5) also in (Joshua 15:8) and Josh 18:16 It is translated in the Authorized Version "the valley of the giants ," a spot which was the scene of some of David's most remarkable adventures. He twice encountered and defeated the Philistines there. (2 Samuel 5:17-25; 23:13) etc. Since the latter part of the sixteenth century the name has been attached to the upland plain which stretches south of Jerusalem and is crossed by the road to Bethlehem --the el Bukah of the modern Arabs. (This valley begins near the valley of Hinnom, southwest of Jerusalem extending toward Bethlehem. It is about a mile long, with hills on either side. This agrees with Josephus and is the generally-accepted location of this valley. --ED.) Tobler, however, in his last investigations conclusively adopts the Wady Der Jasin , on the northwest of Jerusalem. The valley appears to derive its name from the ancient nation of the Rephaim. [GIANTS]