The original coin mill found inside the Casa de la Moneda Museum. This wooden coin press is a hydraulic mill that was used to mint coins in Spain during the 17th century. It is on permanent display at the Real Casa de Moneda in Segovia, Spain in the Sala de Laminacion y Acunacion.
The press consisted of four wooden wheels, three on the interior and 1 on the exterior. The exterior wheel is moved by the fall of the water from the river outside. It is connected to the press on the inside of the building where a system of gears moves the three wheels that power the press.
The interior wheels move two cylinders that perform the work of laminating or coining by pressing metal into dies that were molded to the shape of the coins to be created. The mill can be started or stopped by means of a handle that opens or closes the passage of water that falls on the outer wheel.