Astronomical Clock Prague
A truly marvelous sight, the Astronomical Clock is a 600-year-old marvel of medieval engineering that sits on a gothic tower. The clock is highly unusual and complex and features two dials. One represents the motion of the sun and the moon, and the other one details the signs of the zodiac.
Every half hour Jesus himself marches out, followed by his disciples. The Grim Reaper also rings a bell - checking to see whose time has come (unsurprisingly, everyone shakes their heads 'no').