From BiblePortal Wikipedia

Smith's Bible Dictionary [1]

Ches'alon. (Hopes). A place named as one of the landmarks on the west part of the north boundary of Judah,  Joshua 15:10 probably Kesla , about six miles to the northeast of Ainshems , on the western mountains of Judah.

Fausset's Bible Dictionary [2]

"The side of Mount Jearim (forests) which is Chesalon" ( Joshua 15:10.) A landmark N.W. of Judah. Now the village Kesla , eight miles W. of Jerusalem.

Hastings' Dictionary of the Bible [3]

Chesalon . Near Kiriath-jearim on the border of Judah (  Joshua 15:10 ). Now the village Kesla on the hill N. of Kiriath-jearim.

Morrish Bible Dictionary [4]

Border-city of Judah on the N.W.  Joshua 15:10 . Identified with Kesla , 31 47' N, 35 3' E .

Holman Bible Dictionary [5]

 Joshua 15:10Jearim

Easton's Bible Dictionary [6]

 Joshua 15:10

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [7]

(Hebrews Kesalon ´ , כְּסָלוֹן , place of Confidence; Sept. Χασαλών v. r. Χασλών ), a place named as one of the landmarks on the west part of the north boundary of Judah, beyond Mt. Seir, and apparently situated on the shoulder (A. V. "side") of Matthew Jearim ( Joshua 15:10). This last, the "Mount of Forests," has not necessarily any connection with Kirjath- Jearim, though the two were evidently, from their proximity in this statement of the boundary, not far apart. (See Jearim). Chesalon was the next landmark to Bethshemesh, and it is quite in accordance with this that Dr. Robinson has observed a modern village named Kesla, about six miles to the N.E. of Ainshems, on the western mountains of Judah (Researches, 2:364, note; Later Res. p. 154). Eusebius and Jerome, in the Onomasticon (s.v. Χαλασών , Chaslon), mention a place of a similar name, but they differ as to its situation, the former placing it in Benjamin, the latter in Judah: both agree that it was a very large village in the neighborhood of Jerusalem. The position of the border-line at this point determines that it lay within Judah. (See Tribe).

International Standard Bible Encyclopedia [8]

kes´a - lon ( כּסלון , keṣālōn  ; Χασλών , Chaslō̇n , Χασαλών , Chasalō̇n ): One of the cities on the Northern boundary of Judah ( Joshua 15:10 ). In the 4th century it was a "very large village." It is now Keslā , 2,087 ft. above sea-level, a small village perched on a mountain ridge to the South of Wady el Humār . See Palestine Exploration Fund , III, 25, 26; Sh Xvii .