Where can I find Loot Chest?

I cant find how to get loot chests on farcry 3 for PS3 they are
Thurston Town in a house doors are locked window i can see it its at X,584.5, Y.475.7
Another on top of a hill with a metal door which i cant open its where pirates was its not the ones on top its the ones below its at X.214.5, Y.501.2
Its near Birdhouse tower its in the middle of the river on a little island X.730.7, Y.710.3
Thanks