The Pottery Chimú Vessel is the 6th treasure in Uncharted 3: Drake's Deception.
The Pottery Chimú Vessel can be found in Chapter 2 - Greatness from Small Beginnings.
After eating the rotten fruit, follow Sully until you see a blue truck on your left with sandbags next to the back tire. Instead of following Sully through the archway in the distance, go to the first blue fruit stand on the right after the blue truck. The treasure is at the pottery stand behind this fruit stand.