In The Last of Us, players can find several different cache rooms that are behind shiv doors. Shiv doors are doors in the world that have to be unlocked with a shiv. Throughout the world and storyline, there are a total of 13 locked doors. So, remember to regularly craft shivs and utilize stealth to save on crafting materials.
Outskirts Shiv Doors
The First Clicker
After accepting the role of smuggling Ellie and getting caught by patrol officers, players will escape to a nearby dilapidated skyscraper. This first locked door will be in this building and can be found almost immediately after the cutscene where Joel is attacked by a Clicker. Go into the open room that has a couple of vending machines in the back-left corner. Through the door in this corner is a closed white door. This is the shiv door.
After crawling through the debris-ridden room in the Museum, players will be led out into a hallway with large chandeliers. Take an immediate left down the hall through half-open doorways, then take the open door to the left. It should have a flag hung up to the right of the doorway. This takes players to the kitchen area of the Museum. The shiv door will be to the immediate right.
Bill's Town Shiv Doors
On the Approach
As Joel and Ellie approach Bill's Town, they will enter through the first layer of barbed-wire fence. Drop down through the open fencing and keep left. On the next dropdown, players will find the heavy, metal shiv door on the left wall.
Marquis Music Store
Head around the right side of the Marquis Music Store to reach the back end. Watch out for the tripwire bomb near the end of the wall; it should work perfectly against the approaching clicker. After reaching the backside of the store, players can spot the shiv door on the back wall with a concrete porch.
Pittsburgh Shiv Doors
After defeating the absolute hoard of scavengers in the Kingston Bookstore, players can find this shiv door hidden away in the back corner. Go to the upper floor and head back to the Rivers Cafe. This door isn't in the cafe but in the back-right corner of this floor, beside the Dawn of the Wolf poster.
X Marks the Spot
After the cutscene out in the swampy area of Pittsburgh, turn immediately to the left. The door to the Regal Apartments is marked with a large red X. This is the shiv door.
The Irrational Depot
After another big fight with another group of scavengers in the Financial District, players will find a Ration Depot on the right side of the intersection, spray-painted to say "Irrational Depot." Head through the front doors and the doorway to the far right. This shiv door is a large, blue-gray, metal door through here.
Henry and Sam
Shortly after meeting brothers Henry and Sam, the group decides to work together to escape the city. After heading down the first flight of stairs while following Henry, players will find a large, light, wooden door straight ahead of them. This is a shiv door.
Tommy's Hydroelectric Dam Shiv Door
Players should easily spot this one when they first approach the dam. It is a large metal door at the top of the rusty steps toward the hydroelectric dam.
The University Science Building Shiv Door
After arriving at the University on horseback, Joel will have to explore the various buildings on campus. In particular, the Science Building is where he'll want to look. Entering through a giant hole in the brick wall on the upper floor, players will want to head out the door and take a left down the hall. At the very end of the hallway, the shiv door will be on the right.
For those who might have trouble with directions, the door is a lecture room labeled Room 104.
The Lakeside Resort Shiv Door
On Joel's way to save Ellie, he'll have to pass through several snowy environments. This shiv door can be found across the street from the gas station at the motel. Enter through the open door of the motel, head immediately to the bathroom in the back, and go out the busted window. The shiv door is immediately on the left (more so a large wooden gate than a door) into this back shed.
The Bus Depot Shiv Door
After escaping the resort, Ellie and Joel will travel along an old flooded subway route/bus depot. Since Ellie can't swim, Joel will have to explore most of the areas without her help or put her on floating palettes. When first entering into the underground tunnels, Joel and Ellie will head through an electric-fenced safe zone with a crafting table. When going through the door to the next room, there will be a sign pointing players to the left. Go right instead, and the shiv door will be right there.
The Firefly Lab Shiv Door
Finally, after Joel decides that the Fireflies cannot keep Ellie, he storms back into the hospital that they are using as their lab site. The shiv door can be found on the sixth floor of the hospital. After making the long climb up the spiral staircase to the sixth floor, head in through the door. Jump over the countertop here and the shiv door will be on this inner corner.
It is labeled Room 605 and will have a window on the front wall so players can see if they really need what is inside.
For more The Last of Us content, be sure to check out Last of Us 2: Relic of the Sages Trophy (Strange Artifact) on Pro Game Guides.