Below is a guide on the 4 artifacts and 2 trading cards that can be found during The Tunnels chapter in The Last of Us Part II.
Trading Card – Mortem
This card can be found on the ground floor behind the display counter in the display shelves along the wall. You will need to smash the glass on the far right one to retrieve the card.
Artifact – Program for Cassandra
This artifact is on a green crate to the left of the display counter on the ground floor.
Artifact – Lone FEDRA Soldier Journal #2
This artifact can be found on a desk on in the projector room on the third level.
Trading Card – Beyond
This card can be found on the second level at the end of a hallway past the bar under a couch used to barricade the door.
Artifact – Lone FEDRA Soldier Journal #1
This artifact can be found on a table near a makeshift fort on the balcony overlooking the lobby.
Artifact – The Sick Habit Flyer/Set List
After you turn on the generator and find the key, use it to unlock the door on the ground floor. This artifact can be found on a trunk in the middle of the stage on the ground floor.
Click here for the next guide on the collectibles in The Birthday Gift!