The Mengenlehreuhr (German for "Set Theory Clock") or Berlin-Uhr ("Berlin Clock") is the first public clock in the world that tells the time by means of...

The Mengenlehreuhr (Berlin Clock) may be the "Berlin Clock" the encrypted message references....

13 metres (43 ft) high water clock of communicating vessels, and the Mengenlehreuhr originally located on nearby Kurfürstendamm. The basement is home to...