Chapter 11: In Plain Sight
After completing the Founders Puzzle in the church you will go back outside to the market square. After opening a door, Sully and you will lean over a balcony (cutscene). Put your controller down and don't do anything for 30 seconds. Then the trophy pops.
This is a reference to a mess-up at Naughty Dog's E3 demo of this level. A developer couldn't find the controller on stage and so Nate was just standing around for 30 seconds and they restarted the demo. It appears the guys at Naughty Dog have a good sense of humor though, and made a trophy of it. Awesome!