Chapter 1: Prison
Found at the very start of the chapter. Crouch and check the perimeter of your cell to find this inside a little nook.
Gold Bar #1
Just after passing the upper hall filled with Super Soldiers, you'll use your pipes to climb into a vent. Take a right at the first fork to grab this collectible at the end of the shaft.
Gold Bar #2
Soon after, you'll learn to break crates using melee attack. Continue down this hall, and in the next one, check behind the red-light cart for another set of gold.
Gold Bar #3
After taking the elevator down, look for this bit of wall you can climb in the next hall. Scale it to find a gold item atop a walkway.
Gold Bar #4
When you reach the cells, you'll pry open some trap doors to find a sewer system. Check the northwest corner to find a gold item down here.
Gold Bar #5
In the next cell block, you'll find more gold behind some bars. Head through the nearest kennel entrance to access the cell and pick it up.
Gold Bar #6
After escaping from the giant robo-dog via the air ducts, check this little side cell before dropping to the lower level. You'll find armour, health, and more gold.
Gold Bar #7
After crossing the water on the eastern side of the map, look for some breakable crates near some steps. Behind these is small passageway you can crawl through. Duck inside to find more gold.
Gold Bar #8
Once you've taken out the second Commander, move past the barge power lever to find the last chunk of gold sitting on a bench.