Destiny loot cave：

　　At the far edge of the map Slums there is a secret entrance to a cave which contains 2 loot chests.

　　Make your way from the waypoint towards the cave entrance, you will have to swim into the cave.

　　Once you get in the cave zombies will spawn, kill them and open the loot chest on the left.

　　Once that is done you can go even further into the cave by going to the right side where a small opening will be.