well... would be nice if you specify your Q more. more input = more output, you know :p i ll just list what i know: you can completly avoid this quest if you dont find the "starting location of it" it is located in old haven, at the left from the new u station. you have to find 3 keys and one safe to complete it. then you are send to the dahl headlands to find another safe where a red chest is in. but one after in another.
when you arrive in old haven, head left. there are no enemies, but you can see a loot symbol on your echo device. where it points you find lots of bandit corpses and a key. by pcking up the key the quest log appears and if you accept it, you have to find the other 2 keys and the safe. it all located in old haven and your echo device will tell you where. after finding the 3 keys and the safe, you can enter the safe. there is a note that the real treasure is in the north of the dahl headlands. go there, and at the slope where the map already ends, you ll find the safe with a red chest. try it!