On this page of our guide to Uncharted 2: Among Thieves you will find a detailed description of secrets and collectibles available in Chapter 6 - Desperate Times. Our step-by-step walkthrough explains how to find all (6) secrets hidden in the sixth chapter of the main campaign.
The first treasure is located in the central part of the square where you arrive at the very beginning of this chapter. To get it, you have to climb the signboards attached to the lamp (next to the truck and an opponent with a rocket launcher). The desired item is at the very top, and it is impossible to knock it down with a gun.
The second treasure was attached to the symbol above the entrance to the temple. It's also located on the square at the beginning of the stage. Shoot at it so it falls to the ground.
The third treasure was hidden on the roof, next to the previously mentioned square. In order to get it, you have to wipe out all your enemies and then boost Chloe up by the fire escape staircase. Then climb up the stairs and get to the roof of the building (this is a mandatory path - not any optional activity associated with the treasure). Before you enter the building through a broken stained-glass window, go to the end of the roof. A treasure is hidden there.
The fifth treasure is located in a destroyed staircase, on another immobilized elevator. To get it, you'll have to climb the stairs to the top and jump towards the elevator shaft. Jump into the shaft to land on the roof of the elevator and pick up the treasure. You will locate this staircase shortly after you walk (by holding onto wooden beams) under the corridor which connects the two buildings.
The penultimate treasure was hidden in a suitcase on the roof. As can be seen in the attached picture, to reach the suitcase you will have to jump over the railing and go behind a corner of the building. This place is located near a corridor which connects the two buildings (after you pass it through) and next to the area where the concrete part of the building sticks out over the street.
The last treasure is a bit easier to notice. It can be found in the area where you will encounter (for the very first time) an enemy equipped with a grenade launcher. It was hidden on a canopy with a water tank.