For those who have not completed Xenoblade Chronicles X, this page may contain spoilers regarding the plot. Discretion is advised.
The Ganglion Weapons Hangar is an area in Xenoblade Chronicles X. It is located in Cauldros, within the larger O'rrh Sim Castle Ruins. It is an enormous megastructure approximately 800 meters wide, including the immediate outer wall. (By comparison, New Los Angeles is about 1900 meters wide, including its outer wall.) The roof of the hangar is dominated by an approximately 650-meter-wide metal iris that can open and close to accommodate large craft; when closed, the roof resembles a giant metal colosseum.
The hangar can be technically be visited on foot as soon as the player can explore Cauldros, but both the hangar and much of the path leading to it are filled with enemies over level 40 that make it difficult to explore when under-leveled. At this point, the central hangar chamber is completely empty when explored.
After Chapter 11, the iris is permanently open, and the hangar can be visited from the sky. Again, it will be completely empty.