Chapter 8: Dig Site
Gold Bar #57
Near the start of the chapter, the path splits. Take the right path to reach a heavily guarded graveyard. From where you enter, check the tomb on the right to find a gold bar next to a coffin.
This is found down the left path at the chapter start. One of the Commanders hangs out in the barrack next to the tower - check atop the table inside to find the game's final letter.
Gold Bar #58
Just south of the barrack is an open tomb you can drop into. Follow the path to find more gold inside a little tunnel.
Gold Bar #59
After taking the elevator down, you'll find yourself opposite another Super Soldier. Check the cabinet to the left of this route to find gold on the bottom shelf.
Gold Bar #60
Now duck into the wooden entryway near the cabinet. In this tunnel is a wall you can pipe-climb. It leads to a Commander, but on the desk next to him, you'll find another hunk of gold.
Gold Bar #61
Head to the far western end of the Super Soldier's route to find a small pool of water. Hop in and swim straight down to follow a tunnel into a hidden grotto. There's another gold bar in the water here.
Gold Bar #62
Through the electrical door is a room with a few soldiers firing at something outside. Take them out (they'll all get zombie-fied, for the record), then head up the stairs to the left of your entrance. Hang a right at the top to find some gold at the end of the hall.
Gold Bar #63
The penultimate gold piece is found while descending the narrow, broken staircase. You'll have to leap across the gap to the steps where it's resting.
Gold Bar #64
The game's final gold bar is found just beyond the room with the flaming floor. Fight off the zombies until the stairs are in place, the exit into the hall. You'll find this nested in the rocks to the left of the stone doors.