Gear: Blacksmith's Hammer
Inside the building in the northwest of Bodilsburg Garrison. Defeat the Elite on ground level to get the key.
Go one floor up and shoot the wooden barrier in the ceiling.
Climb up and open the chest.
Contains: Blacksmith's Hammer
The Nickel Ingot is inside a snake pit.
East of Londinium Amphitheatre.
The chest is inside a locked, guarded house. The key to the house is outside underneath a red tent.
Once inside, move away a shelf to get to the chest key.
Reward: Iron Cloud - Light Bow
Londinium Bureau - 1
Go to the Londinium Bureau Office location on the map.
You will see high branches in a circle that you can't penetrate.
Climb high up and take a dive from a branch above the map marker to dive into the Londinium Bureau.
Here, you can dive underwater to get behind the locked office.
Near the hanging platform, you can dive again to get the Nickel Ingot underwater.
Londinium Bureau - 2
Gear: Hidden Ones Mask
Then climb onto the platform and one of the ropes.
From here you can shoot an oil jar inside the office to open up the stone barricaded entrance.
Now you can go inside and collect the Armor chest and the codex page.
Londinium Bureau - 3
Outside, Northwest of the Londinium Bureau, at a small bandit camp.
The chest is underwater.
The secret entrance is underneath the bandit camp's steps into the water.
Dive down towards the stairs and smash the wooden barricade.
Then dive all the way straight ahead to get the chest.
Temple of Mitras
Gear: Briton Shield
You reach the temple on the surface in a guarded area. Stairs are leading down to a gap in the wall.
Here, in the long corridor, stay on the left side where 2 stone shelves can be moved.
One of them hides a slide-through passage.
Go through, follow the path down and open the chest.
Contains: Briton Shield
Temple of Sulis Minerva
The Nickel Ingot is in a closed puma cage.
Climb to the top, where you can shoot down a big cargo pack.
Now you can climb down and claim the treasure.