Armoury Key
From WikiRaider
The Armoury Key is a key found in the level Menkaure's Pyramid in The Last Revelation. The key makes it possible to get a secret in the level, but isn't mandatory in regards of finishing the game.
Getting the Armoury Key might be a bit tricky, because Lara has to kill a Giant Scorpion before it kill an injured soldier at one house in the level. If she succeeds, she gets the Armoury Key in addition to The Guards Keys. If she doesn't, she'll only get the latter.
