The Prague Metronome is a 75 ft functioning metronome in Letná Park, overlooking the Vltava River and the city center of Prague. The kinetic sculpture was erected in 1991, on the plinth left vacant by the late-1962 demolition of an enormous monument to former Soviet leader Joseph Stalin. The silent red metronome was designed by international artist Vratislav Novák, and officially named "Time Machine". It may be the largest metronome in the world, although Geneva (since 1972) and Gdańsk (since 2016) each have a larger pendulum clock. The Prague Metronome is functional, but it is not always in operation. A plaque at the base reads "In time, all things pass..." The inverted pendulum of the motorized metronome has swung at both 4 and 6 beats per minute. The site offers a scenic view of the city and now is mostly used as a meeting place for skateboarders and others.