When you are on Chapter 1-1, you will come across a farm area. It is where you first learn about the blue medallions. After you have finished with the area, go into the large farmhouse, ahead of where you find the note about the blue medallions. Go to the second floor, and then go out the window. You will then be on a walkway. Walk all the way down, and you will see a place with a ladder. Jump down, and go left. When you get to the edge of the fence, look to your left, and there will be a small hidden area with a few crates that have items in them.