The Bright Moon Armory is somewhere within Bright Moon's castle. Prior to the the Battle of Bright Moon, Glimmer had been squirreling away various weapons and armors. She thought she had kept her actions secret, however Queen Angella knew about her daughter's actions and did nothing to stop her.
Prior to the battle, Queen Angella confronted the Best Friends Squad in the armory and presented Glimmer with King Micah's Staff and encouraged the heroes to defend their home.
Bright Moon Armory
Bow prepares for battle
Glimmer accepts King Micha's staff