Flooded Farmhouse Hideout (Location)
A bandit hideout in Yebu Nome. You'll pass through during the Blood in the Water portion of the main quest.
The treasure is in the largest structure visible. You can reach it without being seen by slipping in the northfacing window.
Loot the red box inside to claim the treasure.
You can climb up the remaining spire to snipe the captain, or lure him into the structure with a well (or ill) timed whistle. His death completes the location.