“A Strange City” is the 17th chapter in Dead Space 3 and it contains 4 Artifacts. One of these is located during the Artifact Storage Optional Mission.
Alien Artifact 05
As the cutscene ends and the chapter begins you should look for the first artifact. It is to your right (and a bit behind) next to an ice cube with an alien inside.
Unitologist Artifact 06
As you are tasked with using explosives to clear the path to Carver you will find the artifact next to one of the item boxes. This is also the last Unitologist Artifact and if you followed our guides so far and picked up the others you will unlock the Unitologist Circuit Set.
Alien Artifact 09
As you drop into the room with red markers all around you will get to a T junction. Main mission marker will tell you to go right, but if you go left you will get to do Artifact Storage Optional Mission. You will go through several Zero-G rooms and in the third one you will go through laser traps to reach the top platform. Once you land on the platform look at the walls of the cylindrical room. You will see dark rooms and inside one of them is the artifact.
Alien Artifact 06
As you come back and continue the main mission you will use this “teleport” thing that will propel you through air over a great distance. You will enter an alien door (using the special alien voice code) and as you enter, left, in the dark, you can find the last artifact of the chapter.