Yebu (Location)
An island fortress in Yebu Nome. You'll assassinate someone here during the Unfair Trade side quest.
A good point of entrance is the hidden passage on the east side of the island, as it grants easy access to one of the location treasures.
Enter the passage, and climb up to ground level.
The first treasure is in this building, possibly obstructed by a single guard. Get rid of him to open the carbon crystals for looting.
You can also use this building to lure in and elimante nearby baddies, including the camp captain.
When ready, climb up to the parapets. The next treasure is to the southwest.
Cross the walltops to get there, then drop (or dropkill) down and into the bushes behind the tent.
Enter via the backflap, and loot the red chest for treasure two.
Climb back up to roof level. The remaining two treasures are in the two offices to the northwest.
The southerly one is large white chest, the northern one is red.
The last officer hangs out in the south of the complex.
It's hard to make a sneaky kill with so many people milling around, but you can either pick them off or snipe them out. Either way, the ropes above give easy access to the area.
Off the commander when ready to complete the location.