Prague's Astronomical Clock in the Old Town Square is the oldest clock of it's kind still working.
The Prague astronomical clock, or Prague Orloj, is the third-oldest astronomical clock in the world and the oldest one still working.
It was installed on the southern wall of Old Town City Hall in 1410, and is made up of three main components: the astronomical dial, which represents the position of the Sun and Moon in the sky; the "Walk of the Apostles", a clockwork hourly show (between 09.00-23.00) of figures of the Apostles and other moving sculptures; and a calendar dial with medallions representing the months.
Pražský orloj (Prague Astronomical Clock)
Staroměstské náměstí, 110 00 Prague