The Bhutanese Lime Box is the fourth treasure that can be found in Uncharted 2: Among Thieves.
The Bhutanese Lime Box is found in Chapter 1 - A Rock and a Hard Place. Shortly after the third treasure was found you'll encounter a random enemy. After the explosion takes out the bad guy, continue onward and you will eventually hit a part where have to hoist yourself up some luggage, do a quick scale and then jump over to a secondary car. Before exploring the car, drop down to the metal crate below and walk *South*. You should see the Glimmer in the snow below. Hop down and collect the treasure.