Prague Astronomical Clock

This 24 hour clock, in the Old Town Square, was installed in 1410, and according to some it is the only astronomical clock in the world that is still working. It has dials representing the movement of 1) the sun, 2) the earth, and 3) the moon. Figures on the clock represent each month of the year and also the Christian apostles. You can read more about it on Wikipedia and here is an image that explains the dials: http://en.wikipedia.org/wiki/File:Schema_Orloj_en.png

Many tourists line up to hear it strike the hour -- charming figures emerge from the upper windows and a skeleton hits a bell, sounding the top of the hour. Very interesting but I can't say I totally get how it works....gotta study astrology a bit more :-).