On the west main at "Amatrice" Shores not far from the Inca Temple, was just looking around ( no quest ) and found this close to shore ( about 200 feet inland in a particle cave )
Another pic below of what looks like a LOT of gold. No icon to open chest, that's why I'm wondering if it is related to the Temple quest?

Another pic below of what looks like a LOT of gold. No icon to open chest, that's why I'm wondering if it is related to the Temple quest?
