The Astronomical Clock located on a side tower of the Old Town Hall (reasonably enough, on Old Town Square) is easy to find—just wait until a few minutes before the hour and look for a large group of tourists standing around waiting for something to happen! Still, Orloj is one of the most popular gathering places in Prague. The closer you are to the astronomical clock, the more astronomical the prices in restaurants and stores.Built in 1410 and thought of as an example of 15th century high-tech device, projected with the participation of maths and astronomy professors at Prague University. The main dial is in principle a mechanical astrolabe, showing not only the current time, but also the placement of the sun and moon in the Zodiac, phases of the moon, the times of sunrise and sunset, length of astronomical night, the time in old Bohemian hours, in unequal hours and other data. From gathering crowds, hardly anybody understands all data astronomical dial displays.Then there is a slow-moving 12-month calendar with incredibly delicate, small figure paintings by 19th century Czech painter Josef Manes. Every day on the hour, the upper, glockenspiel-style section of the clock performs the same scene: Death waves an hourglass, the 12 apostles shuffle past small windows, and a rooster crows. After the hour strikes, a Turk wags his head.Long after the Turks had ceased to be a threat in Central Europe, their use as an allegorical figure in genre paintings and other art continued. The Czechs often sided with the Hungarians in various battles against increasing imperial power as exercised by the ruling Habsburg family over their dominions, and though the Turks never occupied Prague as they did Budapest, both countries' artists used "the Turk" (a dark-complected figure, usually wearing a turban) to represent the dangers of the world, and especially threats to Christianity. In the astronomical clock, the Turk is meant to be the stranger.There is a legend about the clock that states the original master builder of its interior clockworks was blinded by the King who commissioned it after the work was completed so the mechanic could never build such a wonderful clock for someone else. In vengeance, the master builder committed suicide by throwing himself into the gears of the clock, which took nearly a century to be repaired. Pickpocketing is common in this location.