There are 4 Napoleon's Bicorns to be obtained in the Quarry District. There are 27 total scattered throughout Franciade.
Description
Use the Northern Underground entrance in the Windmill District. This will lead you directly to the large room with a central shaft that you descended through. You are going want to head to the Outskirts of the room. Use the Western wall to climb up a level or so. This will let you easily jump onto the central structure and get to the Bicorn that is sitting on the Western ledge.