This achievement involves the collecting of 11 different keys, some easy and some not so easy.

Auchenai Key
This key opens up the heroic mode of the Auchenai instances; Auchenai Crypts, Sekketh Halls, Mana Tombs and Shadow Labrinth. This Key costs 10 gold off Nakadu, lower city quartermaster in Shattrath. Requires reputation of honoured with lower city.

Key Of Time
The Key of Time opens Heroic mode Durnholde and Black Morasses. This key costs 10 gold off Alurmi, Keepers Of Time Quartermaster in Tanaris. This key requires honoured reputation with the keepers of time. To gain reputation with KOT you have to run the two instances, completing Durnholde before you are allowed to enter Black Morrasas.

Shadow Labyrinth Key
This drops in Sekketh Hall's in a box after Talon King Ikiss, all party members are allowed to loot this key, you will then be able to open the doors to the shadow labyrinth.

Shattered Halls Key

This was the most fun key to get, remember all those times as a lvl 60 being trample by the Fel Rever well now its payback time.
1.(67,37) Shadowmoon Valley, Drops from Smith Gorlunk.
Near the entrance to the Black Temple, there are two side's the smith is on the left side just up the first ramp, there are lots of high mobs and elites here, east to do if you can fly. HE drops the mold which starts the quest chain
2.(56,66) Force Commander Danath Trollbane.
Trollbane is up stairs in the middle of the fort
3.(51,60) Grand Master Dumphry
Dumphy is wandering around the west tower outside of honour hold, he will ask you to bring him
4 fel iron bars
2 Arcane Dust
4 Mote of fire
Then he will instruct you to kill a Fel Rever.
4. Kill a Fel Rever
All those time he hunted you down now it time to get him back, kill the Fel Rever and
use the key mold on him. Return to Dumphry and you will have the key.

Skeleton Key
This is the attunment for Scholomance, starts in Chillwind camp in Western plague lands and has you running around plagues lands and to Gadgetzan
1.Western plague lands
Get quest “Skeletal Fragments” off Alchemist Arbington
Enter Andoral and kill skeleton until you get 15 fragments, ghouls and abominations do not drop the fragements, return to Arbington and hand in. Pick up quest “Mold Rhymes with “
2.Gadgetzan,Krinkle Goodsteel
Take 15 gold and 2 Thorium bars to Krinkle, he exchanges the 15 gold for a skeleton key mold.
3.Fire plume ridge
Take the mold and thorium bars to the top of fire plume ridge, using this here will give you an unfinished skeleton key.
4.Western plague lands, Alchemist Arbington
After picking up the quest Return to Andorhal and kill Araj The Summoner
5.Return to Arbington to collect you key

The Violet Hold Key

This is most probably the easiest key to obtain, Enter the violet Citadel and pick up the quest off Rhonin the leader of the Kirin Tor, you need to be level 75 to pick up this quest. He then directs you to Warden Alturas outside the Violet Hold, you will be presented with the key in order to complete the next quest.

The Crescent Key

This key is needed to open the west and North of Dire Maul, It involves chasing an imp around dire Maul East Until you get to Pusilin.

To Get to Dire Maul East enter the central Arena area and turn right, it will be the only instance without a locked door, as you enter on the left will be the small imp. Basically its hide and seek, you talk to him he tell you that you have to catch him, he runs off and hides in a bunch of mobs, kill these and then talk to him again before he runs off. This goes on around the outside courtyard in an anti clockwise direction until he goes down a hallway, there are stealthed demons here. At the end of the hallway it will open up into a bigger room with more demons in and to the right is a ramp leading up, this is where pusilin is. Go up ramp, talk to him again then you need to kill him and his imp minions then you get your key.

Shadowforge Key

This is the blackrock depths key needed to access the second half or otherwise know as the quick way through BRD. This key is the reward from the quest “Dark Iron Legacy”.
To pick up this quest you MUST BE DEAD. Just after the summoning stone in the room below is Franclorn Forgewright, you can only see him when you are in ghost form, you have to speak to him and go through his messages then he will give you the quest. You have to collect a hammer and take it to a shrine both of which are inside the instance.
As you enter the instance go straight ahead, the turn first left in the hallway. You should enter the arena, you will fight some beast's and the the boss an Arachnid. By completing this the mobs above you in the arena have turned to neutral, do not try to attack these as they will all attack back in big numbers. Go up the stairs to the arena, follow the circle around and exit the other side, go through here until you reach a small set of stairs go down and take a left, the second right here is where Fineous Darkvire is, you will need to kill him to get the hammer. Now go back to the stairs and instead of going up go straight ahead you will find the shrine of Thaurissan here. Place the hammer in the shrine and get your key.

The Scarlet Key

This is need to unlock Scarlet monestry Armoury and Cathedral and also the scarlet part of Stratholme. The instance is located in Trisfal Glades, the library is on the right hand side of the instance block. Fight your way to the end of the Instance to Arcanist Doan, after killing him there will be a chest, inside the chest is the key.

Workshop Key

The workshop key is used to unlock the back door to Gnomeregan, it drops from Electrocutioner 6000.

To get to him jump down in the first room or follow the upper circle and enter the last corridor on the left, pass through the clean zone and go left. Both ways you reach the bottom area with slimes and elemental s. Enter the large tunnel leading downwards. At its end you'll be on yet another circle. In the middle of this big room is a column and a ramp is leading from the upper ring to this podium where he is. All party members can loot this key.