Meridian trench

The meridian trench, sometimes called the Polar Trench, was a trench situated near the north pole of the Galactic Empire's Death Star battle station. It contained its only weakness, the thermal exhaust port. After the Alliance to Restore the Republic managed to steal the plans to the Death Star, they discovered that fatal flaw. Consequently, the Alliance decided to send an attack run of starfighters down the meridian trench in order to fire a proton torpedo into the exhaust port, triggering a chain reaction that would cause the Death Star's main reactor to explode. After navigating his T-65B X-wing starfighter through the meridian trench, Luke Skywalker managed to destroy the battle station as planned.

Text and facts from the “Meridian trench” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.