History!

It certainly tells a story. Eclectic use of multiple different building materials, modifications over the years -the filling in of that doorway for instance. I believe the current cathedral was started in 1181 but that there has been a church on the site since the 6th century. The present cathedral was badly damaged in an earthquake in 1246.

Colour is really essential for this picture. It would not tell the story of the building so well in monochrome.