What does Joshua 18:16 mean?

then down to the foot of the hill facing the Valley of Ben Hinnom, north of the Valley of Rephaim. It kept going down the Hinnom Valley, south of the Jebusite city, and on to En Rogel. Joshua 18:16 - Modern Text Bible

(This verse traces the border through valleys and past the city of the Jebusites (later Jerusalem).)