A coin watch or medal watch comprises a watch inserted into a coin or medal.
A coin watch is typically made by slicing a coin into two disks, one thinner than the other; or by removing one face of a coin. A watch mechanism is then embedded into the thicker part, and the two faces joined by a concealed hinge and catch. When closed, the watch is hidden and the coin looks like any other.
Noted makers of coin watches include Cartier and Corum.