A place of lookout or post of observation, often built on a city wall. (See TOWER.) Other watchtowers were constructed in wilderness areas or on frontiers. They were principally designed for military purposes and served to protect a city or a boundary; they were also constructed as places of refuge for shepherds and farmers in isolated areas and enabled a watchman to warn of marauders so that flocks and ripening crops in the area might be protected.​—2Ch 20:24; Isa 21:8; 32:14.

A number of cities were named Mizpeh (Heb., mits·pehʹ, “Watchtower”), probably because of being on high elevations or because of notable towers erected there. Sometimes the Bible distinguished these cities by naming their location, as “Mizpeh of Gilead” (Jg 11:29) and “Mizpeh in Moab.”​—1Sa 22:3.

A pile of stones was set up by Jacob and called “Galeed” (meaning “Witness Heap”) and “The Watchtower.” Laban then said: “Let Jehovah keep watch between me and you when we are situated unseen the one from the other.” (Ge 31:45-49) This pile of stones would testify to the fact that Jehovah was watching to see that Jacob and Laban carried out their covenant of peace.