Built in 1410, the Astronomical Clock in Prague is the oldest functioning clock of its kind in the world.  With approximately 350 parts the clock has faultlessly told time, be it Babylonian or old Czech allowing people to tell the time of sunset.  It can indicate the position of the moon and the sun; shows the constellation the sun is currently in and the phases of the moon.  Then every hour on the hour there is a procession of the 12 apostles where the statues of vanity, lust, greed and death all move.  If that is not enough to impress you, it ingeniously doesn’t move for a night during leap year!