The largest valley in Jerusalem is called Emek Rephaim in which the neighborhoods of Katamon, Mekor Chaim and Baka are located.
The name Rephaim comes from the name of a people that inhabited the land before Jews entered it. They were exceptionally large and the very sight of them caused people's hands to become weak – ropheh in Hebrew – hence their name Rephaim.
In ancient times this valley served as farming land for Jerusalemites.