A skeleton watch is a type of mechanical watch where the moving parts are visible, either through the front, back, or a small cut outlining the dial. True skeletonization involves trimming away non-essential metal from the bridge, plate, wheel train, or other mechanical parts, leaving only a minimalist 'bare' skeleton necessary for functionality. The remaining movement is often decorated with engraving. Skeleton watches can also feature designs like the “semi-skeleton,” which has a partial cutaway of the watch face, and the “open heart,” which includes a window to view the oscillation of the balance wheel. These watches are known for their intricate design and craftsmanship, often considered luxury items due to the complexity and skill required in their creation.