The astronomical clock of Lund Cathedral, the Horologium mirabile Lundense, was constructed c. 1380.

On top of the clock there are two knights that mark the hours.

The upper board of the clock is the astronomical clock. It shows, among other things, the different phases of the Moon and where the Sun sets.

The lower board of the clock is a calendar.

With the help of it one can, among other things, calculate when different mobile religious holidays will fall and on which weekday a certain date will fall.

In the middle of the calendar stands Saint Lawrence, the Patron Saint of the Cathedral, and by his side the Symbols of the Four Evangelists.

Top image via Yipski on flickr.
Middle image via The Hamster Factor on flickr.
Bottom image via David Andersson on YouTube.

Via Wikipedia.