John Gill Commentary 2 Chronicles 8:5

"Also he built Beth-horon the upper, and Beth-horon the nether, fortified cities, with walls, gates, and bars;" — 2 Chronicles 8:5 (ASV)

Also he built Bethhoron the upper, and Bethhoron the nether ,
&c.] Only mention is made of the latter in (1 Kings 9:17) ,

fenced cities, with walls, gates, and bars ;
fortified cities in the tribe of Ephraim.