Constructed in 1410, the Prague Astronomical Clock is the oldest astronomical clock in operation (and the third oldest astronomical clock in the world). The clock itself is comprised of three main components: the astronomical dial, which displays the position of the Sun and Moon in the sky, as well as various other astronomical details; the “Walk of the Apostles,” an hourly display of animated sculptural figures of the Apostles, and others—notably a figure of Death (represented by a skeleton) striking the hour; and the calendar dial, which features medallions that each represent a different month of the year. What it doesn’t tell you, however, is the time of day.
Yet, there is more to this clock than meets the eye–apparently, yet not surprisingly, the clock is cursed, which is part of the reason we cannot use it to tell time:
80 years [after the clock’s initial completion], the legendary master Hanus rebuilt the clock. As legend has it, the Councillors had him blinded, so that he would never manage to build another instrument greater than the Orloj in Prague.
The story also says that before he died, master Hanus deliberately damaged the [time-telling aspect of the] clock so seriously, that nobody could ever fix it again. He also cursed the instrument, so those who tried to repair it have either gone mad or died.
For more information, read more here and take a look at this great video explanation of the astronomical clock:
And a very cool celebratory display for the clock’s 600th birthday!