The Idrija Kamšt is a pumping device in the Idrija mercury mine with the largest wooden wheel in Europe. Kamšt is the mining name for a water-powered pump for pumping cave water, typical of Idrija. The name comes from the German word "Kunst" (art).
In the past, there were several Kamšts in Idrija, but only the largest of them has survived, which pumped water from the Jožef shaft. It was built in 1790, and the diameter of the wheel measures 13.6 meters. The wheel was connected to a 75-meter-long horizontal wooden frame. The horizontal movement was transmitted to a vertical wooden pole, which was connected to step-by-step piston pumps. In one minute, the Kamšt pumped up to 400 liters of water, first from a depth of 235 m, and later even from a depth of 283 m. Due to its efficient pumping, it operated until 1953, i.e. for 163 years. The driving water flowed through a special canal called Rake, 3.5 km long, which was built around 1600 for the supply of driving water. The power of the Kamšti was between 75 and 100 horsepower, and the wheel took 13 seconds to make one revolution.