The astronomical clock is on a side wall of the square tower of Prague's Old Town Hall. The clock dial shows the earth at the center of the universe, surrounded by the planets. Below the clock is a calendar with symbols of the zodiac.
Crowds of tourists often gather in the plaza to watch the astronomical clock strike the hour. When the bell in the tower tolls, windows above the clock fly open and mechanical apostles, skeletons, and sinners pop out and begin to dance.
