"World's Oldest Working Astronomical Clock Prague's Astronomical Clock is the world's oldest working one of its kind. Installed in 1410, it is located on the Old Town City Hall in Prague 's Old Town Square. The medieval clock features an astronomical dial; "The Walk of the Apostles", an hourly show of moving sculptures; and a monthly calendar dial with the 12 signs of the zodiac. The clock is the center of Prague and the city's most popular sight. On the top of every hour, huge crowds gather to watch the movement of the Twelve Apostles. Two doors on either side of the clock open and the statues become animated with twelve moving disciples. Animated statues representing greed, vanity and death also add to the performance, which during the Middle Ages was one of the man-made marvels of the world. For centuries it has been displaying the time and date, the position of the sun, the phase of the moon and astronomical cycles. Even in the age of smart phones, that is pretty impressive! It's easy to spend a whole afternoon, if not a whole day, here. You can visit the Town Hall, climb to the top of the tower for one of the best views in Prague, watch an Astronomical Clock performance, then enjoy a Czech meal in one of the local restaurants."