Below is a guide on the 3 artifacts, 5 coins, 1 safe, and 1 weapon that can be found during The Descent chapter in The Last of Us Part II.
Coin – Illinois
This coin can be found at the very bottom of the pool on the drain.
Artifact – Gym Safe Combo
This artifact can be found on a bulletin board in the kitchen of Orchards Juice Bar, which is just past the gym.
Safe
The safe is located in the green door across from the gym. The safe code is 12-18-79, which can be found on the free WIFI sign on the wall in the gym.
Artifact – FEDRA Orders
This artifact is obtained automatically as part of the story.
Artifact – FEDRA Final Note
After climbing down the fire hose as part of the story, head through a broken section of wall on the right to find the artifact next to a corpse.
Weapon – Flamethrower
After getting attacked by the Infected growing in the wall, follow the path around and jump down to a lower level. Enter through the doorway and turn right following along the windows then jump across the gap in the floor to the room across the way. You will be attacked by a Clicker. Defeat it then keep heading forward through the room. Take a right at the dead end towards a dark hallway. Take a right and squeeze through a cracked door to enter a bathroom. From there, cross over a narrow metal beam and duck through a small opening in the wall. The weapon will be on a corpse to the left in this room.
Coin – Oregon
As you descend down the hotel, there will be a section where you have to walk past two support beams then jump down to the floor below. This will be right after encountering a Shambler. If you get to the really long beam, you went too far. After jumping down, turn around and jump across the gap through another doorway. The coin will be located a shelf to the right.
Coin – Wisconsin
After exiting the elevator shaft on the 4th floor, turn left to find a vending machine. Smash the glass to get the coin to come out into the coin dispenser.
Coin – Rhode Island
This coin can be found in the courtyard with all the couches and the bar. It is behind the bar on the back side.
Coin – Missouri
After getting let through the gate to the hospital, take a right behind the ambulance to find a building. Head through the broken window and follow the hallway to the end to find the coin next to some debris.
Click here for the next guide on the collectibles in Ground Zero!