An Armory.
What I would most likely do is go to the closest store that sells both weapons and ammunition along with food and medical supplies, defend the building with your life.
An arsenal, a weapons cache, etc. Armoury
Ammunition shelf's were where the soldiers kept their ammunition and guns.
Weapons, armor and ammunition.
Weapons are kept in Armouries. Ammunition is kept in a magazine. They should not, never ever, be stored together.
Weapons and ammunition are stored in an armory, magazine, silo, arsenal or at a weapons or ammo dump. In a home they should be stored in a secure safe or chamber/trigger locked with ammunition locked up separately.
Put trigger locks on the weaponsTrain your kids to safely handle weaponsSecure your ammunition and empty your weapons
Arsenal or armory.
Some examples of military weapons and ammunition include rifles, pistols, machine guns, grenades, missiles, and artillery shells.
heavy weapon Ammunition fired in artillery weapons such as cannons, howitzers and mortars.
NO!
The armory.