The Prague Astronomical Clock is a medieval astronomical clock located on the south wall of the Old Town Hall in Prague, representing an important tourist attraction. The three main components of the clock are: The astronomical quadrant, which in addition to indicating 24 hours a day, represents the positions of the sun and the moon in the sky, in addition to other astronomical details. The animated figures that include "The walk of the Apostles", a clockwork mechanism that shows, when the clock gives the hours, the figures of the twelve Apostles. The circular calendar with medallions that represent the months of the year.