I've eared that this very pretty little castle was one of the most photographed monument in France. I don't know if it's true but this place is hugely touristic and you can read anything about Annecy without seeing such an image.
This castel was built in 1132 and is also very well known under the name of Les vieilles prisons because it was used as a jail during a while.
You can learn a little more about it with this english page of Wikipedia and much more on the french page.
And for peoples who like technical info : this image is the result of a HDR work done from 3 exposures and processed with Photomatix and Oloneo PhotoEngine.