Often times a storage place for weapons and ammunition is called an arsenal. In US history one of the most famous such arsenals was located at Harper's Ferry in Virginia.
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.
Weapons, armor and ammunition.
An 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.
Ammunition shelf's were where the soldiers kept their ammunition and guns.
NO!
It all depends on what kind of munitions you are talking about and who you ask. The three most common terms are Ammunition Holding Area (AHA), Munitions Storage Area (MSA), and the Weapons Storage Area (WSA). Within any of these you have magazines, multicubes, igloos, etc.
An arsenal, a weapons cache, etc. Armoury
A secure area where weapons are stored.