Old Town
This first COG Tag is found towards the end of the level. You'll be walking up a path towards the waypoint marking the end of the chapter. Instead of turning left, go to the end and turn right into a yard. On the building at the end of the yard will be the Crimson Omen. If you check the right side of the building, there will be a small alley which will lead to this tag.
Riverwalk District
At the end of this section, look down the hill and you'll see a fountain on the right side. There's an alley that runs near this fountain and there's a small niche in the alley. In that small space will be this COG Tag.
Museum Gardens
When you come out of the building, walk forward a little and watch on the right side for a small alley. You'll see a Crimson Omen and if you follow the alley, you'll find the COG Tags on the ground at the end.
Great Hall
The COG Tags are in the fountain below. You'll have to get in the water and go to the far side of the column to find it.
Kaskur Wing
At the far end of the wing will be a turret on a raised platform. The COG Tag is just under this between a column and the wall.
East Wing
Just before leaving this area, turn right and you'll see a small dead end room. The COG Tags will be in a pool of blood on the floor.
Archives
You'll fight off several enemies in the first section of the Archives before enetering a large room with tons of filing cabinets. When you enter here, hug the left wall and just keep following it. It will take you past a broken elevator and eventually to a little section hidding in the filing cabinets. On one side will be the Crimson Omen and on the other will be the COG Tags.
Vaults
You'll enter the dust filled vaults and have to fight quite a few Locust through the haze. After the room is cleared, keep the giant crater in the room on your right and follow it until you run out of floor to walk on. You'll find the COG Tags here.
