Build a circular medieval tower with an outer diameter of 16...

Build a circular medieval tower with an outer diameter of 16 blocks. The tower must be completely hollow inside, with no floors, pillars, stairs, or internal structures, as it is only meant to cover an XP farm. Use a simple medieval style, with stone-based blocks (stone bricks, cobblestone, or similar) to give a solid and realistic look. The height should be proportional to the diameter (a tall tower), but keep the entire interior empty from bottom to top. Add light exterior detailing and block variation on the walls, but do not add interior windows, furniture, or lighting. The top may be open or have battlements, as long as it does not create any internal platforms or obstructions.