The meridian trench, which is occasionally referred to as the Polar Trench, was a trench located in the vicinity of the north pole of the Galactic Empire's Death Star battle station. It housed its sole vulnerability, the thermal exhaust port. Following the Alliance to Restore the Republic's successful theft of the Death Star's schematics, they uncovered that critical defect. Therefore, the Alliance opted to launch an attack run with starfighters through the meridian trench with the intention of launching a proton torpedo into the exhaust port, thereby initiating a chain reaction that would lead to the explosion of the Death Star's primary reactor. After piloting his T-65B X-wing starfighter through the meridian trench, Luke Skywalker succeeded in annihilating the battle station as initially conceived.