Joshua 18:15

And the south side on the part of Cariath-Baal; and the borders shall go across to Gasin, to the fountain of the water of Naphtho.

And the south quarter was from the end of Kirjath–jearim, and the border went out on the west, and went out to the well of waters of Nephtoah:

The south quarter was from the farthest part of Kiriath Jearim. The border went out westward, and went out to the spring of the waters of Nephtoah.