In Call of Duty: Modern Warfare 4 DMZ, keys grant access to specifically named doors at Hajin points of interest. Check the key’s item card for the location, then verify the door by its matching name when you inspect it. The 19 doors listed here are in places such as hospitals, casinos, police stations and air base buildings; they do not represent every key in DMZ.
Quick answer: Read the grid square on the key’s item card, find that square on the map, then look for the door whose name matches. Press F on PC at the “- UNLOCK” prompt.
How DMZ key doors work
A key’s item card lists its rarity, the word “KEY”, a value, and a short line that starts with a map grid square. The key cards shown below each carry a value of 100. The Mirae key, for example, reads “F5 – Unlocks the electrical room in the northwestern basement parking garage within Mirae General Hospital.” Open your map and locate that square to find the building.
Once you’re inside, aim at locked doors to read their names. The prompt changes depending on whether you’re carrying the right key:
- Without the key, the door shows a padlock and “<ROOM NAME> – LOCKED”.
- With the key in your inventory, it reads “<ROOM NAME> – UNLOCK” (F on PC).
- Unlocking a door such as the Mirae Electrical Room, the casino counting room or the police station armory gives “300 XP DOOR UNLOCKED”; some doors display “300 XP STRONGHOLD UNLOCKED” instead.
- The prompt then switches to “OPEN DOOR”.
The key and door labels may not match. For example, the Counting Room Vault key opens the door marked “HEAVENLY LUCK CASINO COUNTING ROOM”.
Keep keys in a secure slot so you hold on to them if you lose your backpack.
Some keys come from set sources. The Mirae Electrical Room key is the mission reward of Operation Critical Extraction, Operation Shopping Hacks rewards a Coin Mining Den key, and the card for Operation Silent Ledger lists a Counting Room key. The Counting Room Vault key can also be found as field loot: one place it appears is an INDUSTRIAL LOCKER at the Rice Mill in Imjin Farmland, and another is a Military Locker inside the Haksan School Armory at Deadtown. The Doctor’s Command Office key drops from The Doctor, the Lieutenant at Mirae General Hospital.
DMZ key door locations by POI
| Key door | POI | Threat |
|---|---|---|
| Mirae Electrical Room | Mirae General Hospital | LOW |
| Counting Room Vault | Heavenly Luck Casino, Cheongun Village | HIGH |
| Mechanic’s Shack | Cheongun Village | LOW |
| Police Station Armory | Pyeonghwa Village police station | — |
| Militia Arms Depot | Hajin River Heights | — |
| Field Depot | Chang-san Air Base | CRITICAL |
| Re-Education Center Annex | Re-Education Center | MEDIUM |
| Underground Propaganda Store Room | Re-Education Center | MEDIUM |
| Executive Arms Auction | DBN Headquarters | EXTREME |
| Rice Mill Bunker | Rice Mill, Imjin Farmland | LOW |
| The Doctor’s Command Office | Mirae General Hospital | LOW |
| Commandant Office | Admin Complex No. 2 | EXTREME |
| Shop Records Room | Wolves Stadium (F7) | MEDIUM |
| Coin Mining Den | NuriGO West (G6) | MEDIUM |
| Vault Armory | Heavenly Luck Casino Parking, Cheongun Village | HIGH |
| Haksan School Armory | Deadtown | LOW |
| Gun Store Weapons Locker | Gun stores in Cheongun Village (west) and Songdo Wharf (north) | LOW |
| Supreme Leader’s Bunker (access card) | Chang-san Air Base Bunker | EXTREME |
| Hazard Storehouse | Haneul Nuclear Reactor | HIGH |
A second door marked Police Station Armory is inside the police station at Revolution Dam. On the map, Admin Complex No. 2 is located within Chang-san Air Base.
Key rooms with card text or contents
Mirae Electrical Room (Rare)
The card reads “F5 – Unlocks the electrical room in the northwestern basement parking garage within Mirae General Hospital.” Head down to level B2 of that garage. The door is a grey double door in the purple-walled section, under the word “Danger”, with the prompt “MIRAE ELECTRICAL ROOM – UNLOCK”. Inside is a long electrical room with a tool chest, a footlocker and bags. Loot can include Electronic Sensors, an Encrypted Archive, Armor Plates and Electronics.
Counting Room Vault (Epic)
The card reads “F4 – Unlocks the counting room’s vault on the main floor of the Heavenly Luck Casino within Cheongun Village.” Go into the staff area behind the main gaming floor. Look for a dark wooden door with a keypad and fingerprint reader on the wall beside it. Its prompt reads “HEAVENLY LUCK CASINO COUNTING ROOM – UNLOCK”.
Behind it is a storage room with a weapons locker, which can hold a Zip Gun Recipe for the 3D printer. Past that is a vault room lined with safe-deposit boxes, caches and a safe. Loot there can include Nuclear Program Files, an Encrypted Archive and a Gold Skull.
Besides the Operation Silent Ledger reward, the key can be found in an INDUSTRIAL LOCKER at the Rice Mill in Imjin Farmland (map column D, on the row 7/8 line). That card is EPIC, KEY, value 100. The Counting Room Vault key guide covers where the locker stands. A Military Locker inside the Haksan School Armory at Deadtown has also held it: EPIC, KEY, value 100, with the same F4 card text.
Mechanic’s Shack (Rare)
The card reads “F5 – Unlocks the mechanic’s shack south of the clinic within Cheongun Village.” It’s a small standalone hut with a single door, and the prompt is “MECHANIC’S SHACK – UNLOCK”. The single room inside holds footlockers, a rifle case, an armor box, a tool chest, military lockers, a military bag and a duffel. A KG-7 Vulcan and a Power Regulator can turn up here.
Police Station Armory
At Pyeonghwa Village, find the station marked “보안성 · POLICE STATION” and take the main stairs down to the basement. In the corridor by the holding cells, look beside the caged armory window for the door. Its prompt reads “POLICE STATION ARMORY – UNLOCK”; unlocking it awards “300 XP STRONGHOLD UNLOCKED”. Inside are a Basic Weapons Locker and a military bag.
Militia Arms Depot (Rare)
The card reads “G7 – Unlocks the armory on the lower floor of the Gangbyeon Apartment B building of the compound within Hajin River Heights.” One place this key can appear is a duffel bag inside The Citadel East Wing, the cell block at the Political Prison. The Political Prison has a CRITICAL threat level.
Vault Armory
The Vault Armory is a different door from the parking vault gate. From the casino gaming floor, take the white side door and stairwell down to Heavenly Luck Casino Parking (HIGH threat), then go through the grey door by the yellow “통제구역 RESTRICTED AREA” sign. The mesh door in the caged room with a counter window reads “VAULT ARMORY – UNLOCK”; opening it gives “300 XP DOOR UNLOCKED”. Its Weapons Locker can hold a weapon manual, for example “MANUAL: PPSH-41” (“Unlocks ability to purchase this weapon in Gunsmith.”), and a Military Bag can hold Nuclear Program Files. The Vault Armory guide has the full route.
Haksan School Armory
At Deadtown (LOW threat, map columns B/C around rows 6/7), follow the outdoor walkway with red railings in the school building with teal-and-white tiled walls to a red wooden door with a glass panel. The prompt reads “HAKSAN SCHOOL ARMORY – UNLOCK”, and opening it gives “300 XP DOOR UNLOCKED”. The classroom inside is an armory with weapons, a Medium Backpack, a Defibrillator and 3D printer materials, and a Military Locker there held a Counting Room Vault key. See the Haksan School Armory guide for the loot.
Gun Store Weapons Locker (Rare)
This key opens lockers, not a door. The card reads “Unlocks the Weapons Lockers in Gun Stores, found in Western Cheongun Village and Northern Songdo Wharf.” In either store’s back room, the green lockers read “GUN STORE WEAPONS LOCKER – UNLOCK” with the key (“- LOCKED” without it), and opening one gave “375 XP” and “DOOR UNLOCKED”. One key opened one locker; the next locker in the same store still read LOCKED. The Gun Store Weapons Locker key guide covers both stores.
Other locked key doors in Hajin
Most of these doors show their name with “- LOCKED” until you carry its key.
| Door prompt | Where to find the door |
|---|---|
| “FIELD DEPOT – LOCKED” | Chang-san Air Base hangar, white door with red panel |
| “RE-EDUCATION CENTER ANNEX – LOCKED” | Main building, wooden door near “NO PUBLIC ACCESS” |
| “UNDERGROUND PROPAGANDA STORE ROOM – LOCKED” | Re-Education Center underground, off a dark corridor |
| “EXECUTIVE ARMS AUCTION – LOCKED” | DBN Headquarters, dark teal door on a carpeted office floor |
| “RICE MILL BUNKER – LOCKED” | At Rice Mill, look for a green metal door fitted with a circular knob. |
| “THE DOCTOR’S COMMAND OFFICE – LOCKED” | Mirae General Hospital office area, pale wooden door |
| “COMMANDANT OFFICE – LOCKED” | Admin Complex No. 2, off the hallway with red curtains and flags |
| “SHOP RECORDS ROOM – LOCKED” | Wolves Stadium shop, frosted-glass door beside an apartment-sale poster |
| “COIN MINING DEN – LOCKED” | NuriGO West, stairwell landing marked “3”, grey door under the “OFFICE” sign |
| “REQUIRES SUPREME LEADER’S BUNKER ACCESS CARD” | Chang-san Air Base Bunker, blast doors below Admin Complex No. 2 |
| “HAZARD STOREHOUSE – LOCKED” | Haneul Nuclear Reactor, blue door on the “STORAGE” shed |
At Chang-san Air Base, find the Field Depot in one of the corrugated-metal hangar buildings. Take the stairwell to reach The Doctor’s Command Office at Mirae General Hospital; its key drops from The Doctor, and the LT CRATE inside holds the Tempered Armor Vest recipe. At the Rice Mill Bunker door, the HUD displays “Imjin Farmland”. A nearby locked door is marked “IMJIN MILL FOREMAN’S OFFICE – LOCKED”.
For the Shop Records Room at Wolves Stadium (map square F7), enter the shop building through the pair of grey metal-framed glass double doors in the red-brick wall and cross the shop floor with its blue-and-white counters. The frosted-glass door with a metal handle is in a narrow hallway, next to a large Korean apartment-sale poster in a glass case.
The Coin Mining Den is at NuriGO West (map square G6), just west of NuriGO Mall and north of The Grid. Inside a multi-storey building with a red-railed stairwell, climb to the landing with a large “3” painted on the wall. The door is a plain grey door with a lever handle under a wall sign reading “사무실 OFFICE”, with a green exit sign and a red fire alarm beside it. Its key is the Operation Shopping Hacks reward.
The Supreme Leader’s Bunker takes an access card rather than a key: its card reader reads “REQUIRES SUPREME LEADER’S BUNKER ACCESS CARD”. It is at the Chang-san Air Base Bunker (EXTREME threat, map column B, rows 5/6). From Admin Complex No. 2, take the stairwell marked “02” down to the basement and follow the corridor and metal stairs down to a pair of large white blast doors painted “자유” with red star crests; the card reader is on the red brick wall to their right. The “COMMANDER COLOSSUS / CHANG-SAN AIR BASE” banner appears as you reach the doors.
The Hazard Storehouse is at the Haneul Nuclear Reactor (HIGH threat, map column I, on the south shore of the reactor island around rows 4/5). It is a white corrugated storage shed marked “창고 STORAGE” with a light-blue door and blue barrels beside it; the door reads “HAZARD STOREHOUSE – LOCKED”.
Heavenly Luck Casino Parking: vault gate vs Vault Armory
Heavenly Luck Casino Parking is rated HIGH threat and is accessible via the Casino Sewers. Crates sit inside a mesh-caged storage room beyond a locked gate. The gate displays “DOOR UNLOCKS VIA SECURITY SYSTEM”, which means carried keys cannot open that gate. The same garage does have a keyed door: the vault gate opens from the security system, while the Vault Armory behind the “RESTRICTED AREA” door opens with its key (“VAULT ARMORY – UNLOCK”).
