watchtower
n. B2 Upper Intermediate UK //wˈɒtʃtaʊɐ// watch·tow·er
n. a tall tower with a window on the side, used for looking out over a large area. People use it to spot enemies or watch for danger.
n. a tall structure with a narrow opening, typically on the side, designed for observation over a wide area. Often associated with military or defensive architecture.
The guard stood at the top of the watchtower.
From the watchtower, the soldiers could see the entire valley and warn the village of any approaching threats.
The medieval fortress featured several strategically placed watchtowers that allowed for constant surveillance of the surrounding roads and the distant horizon.
From watch + tower.