Building a wall out of differently sized and shaped stones is a real challenge. Especially when the stones have to fit into a given frame. This is the only rule of the wall puzzle - all stones that were in the wall have to fit in there again. Most likely you'll never achieve the same setup again. The wall will look different with every attempt, because each stone can be placed in up to 10 different ways.
How to start: Take all the stones out of the box, set up the frame and start building. Try to keep the gaps as small as possible.