The Bronze Altar Spoon is the thirty-fourth treasure that can be found in Uncharted 2: Among Thieves.
The Bronze Altar Spoon is found in Chapter 8 - The City's Secret. As soon as you gain control in this chapter, you can immediately find the first of two treasures found here. Immediately turn to your right and go through the doorway. On your left, you'll find a place where a staircase once led upward. You can't obviously climb stairs that aren't there, but you can use the wooden remnants along the wall to hoist yourself upward to the second floor. Up here, in front of the gate, you can grab this treasure. You can actually see this treasure's glimmer from the room ahead of you, but you can't grab it from there. Instead, grab it from here before you proceed, and save yourself the headache of having to backtrack.