Location 1 (White Chest)
Next to the broken claptrap. you can not see it though just look around in the corner.
Location 2 (White Chest)
Next to the repair kit.
Location 3 (White Chest)
Next to smoke signal in the apartment district to the north east
Location 4 (White Chest)
Between the rooftop smoke signal and junkyard smoke signal, on the first floor of a building. It can be accessed by first making a difficult jump from the second floor of the rooftop smoke signal building, then a jump west again. Stay on the second floor and walk south. Two white chests can be seen on first floor.
Location 5 (White Chest)
The second of two white chests between the rooftop smoke signal and junkyard smoke signal.
Location 6 (White Chest)
On the ground in a back alley, on the west edge of the map, and directly south of the Fast Travel point.
Location 7 (White Chest)
South east of the entrance vending machines, on the first floor. With Zombie Island of Dr. Ned installed, it can also be seen on the way up to Jakobs satellite station.
Location 8 (Red Chest)
On the first floor in the main street through the middle of Old Haven. It can be accessed by climbing from the back or jumping up from the fuel tank and over the railing, out the front.
Location 9 (Red Chest)
On the rooftop of the building North of chest #8, right behind a fuel tank, marked by two arrows. This is accessed by going to the far north, jumping onto a large boulder, then a red awning and onto a 1st floor roof. From there just two more first floor roofs to get to another fuel tank that can be used to reach the 2nd floor roofs. An alternate route is to jump onto the washing machine on the north side of the next-door building, and from there jump onto the ledge directly in front of you. Edge right along ledge until you come to the roof top. Then jump on the rail to the NW, and then jump on top of the tank. This puts you on the same level as the chest, but one building over; a running jump from one building to the next lands you right by the box.
Location 10 (Red Chest)
Under the stairs near the doorman Claptrap in the Canal District.
Location 11 (Red Chest)
In the rooftop smoke signal area, there is a building south-east of the vending machines with no stair access. The chest is hidden in the corner of a balcony and can be accessed by jumping from the second floor of an adjacent building.
Location 12 (White Chest)
Behind the building where chest #10 and key #3 for Bandit Treasure: Three Corpses, Three Keys is. Go up the stairs and follow the ledge around to the right.