In Summoner’s Rift, the defensive structures guarding lanes are called turrets.
Turrets are fortified structures positioned along the top, middle, and bottom lanes. They automatically attack enemy champions, minions, and other targets that enter their range, making them essential defenses during the push toward an enemy base.
Each team’s base and lanes contain multiple turrets, and destroying them opens safer routes toward the Nexus. Inhibitors and the Nexus are separate structures with different strategic functions, so a turret is not simply another name for every defensive object on the map.
Players often say “tower” in casual conversation, and that term is widely understood. However, “turret” is League of Legends’ canonical in-game terminology. Barracks, outposts, and keeps are not the standard names for lane defenses in Summoner’s Rift.