The astronomical clock in Prague was one of the most astonishing structures that I saw in my trip to Europe.
Built in 1410, this clock shows an astronomical dial along with a calendar dial and the figures on the clock set in motion every hour (which is also an attraction spot for tourists). The 4 figures on the face of the wall represent Vanity, Greed, Death and Lust. Legend says that the city will suffer if this clock is ignored by the people.