For its 150th birthday, the prestigious Wallraf Museum has opened its gallery vaults to reveal the secret treasures inside. 'Panopticon – The Secret Treasures of the Wallraf' is the title of the anniversary exhibition which runs until 22 January 2012 in Cologne's oldest museum.

And if that's not enough culture for you, there are also lots of other museums in the cathedral city of Cologne. The range of topics is incredibly broad, and there's even a museum of chocolate!