Located in the old French watchmaking capital of Besançon, the astronomical clock of Besançon Cathedral is one of the most complicated horological devices in the world.

Installed in 1860, the clock features 30,000 pieces, 70 dials, 122 indicators, the local time in 17 places around the world, the time and height of the tides in eight French ports, a perpetual calendar with leap year cycles, times of sunrise and sunset, an orrery, and 21 automata. Zodiac signs adorn the towering and elaborate exterior. It was constructed by clockmaker Auguste-Lucien Vérité, and over a century and a half later it still is in working order. 

Five dials separate from the clock are also controlled by the mechanisms, including one on the outside of the church showing the moon’s phases and a planet for each weekday, and four up on the bell tower.