Guard towers are tall structures usually found in prisons or military facilities. They are used to watch over and protect the area, preventing unauthorized people from entering and ensuring safety. Full definition
Other than the looming guard towers blocking the sky, everything looks flat. (firstthings.com)
Rising behind them are plywood guard towers, some draped with American flags, and an array of lights for night. (nytimes.com)
Each attempt, while searching for an enemy informant who can tell me where my target is, I'm almost immediately spotted by an enemy guard tower in a nearby camp. (pcgamer.com)