Montségur Fortress, Languedoc-Midi-Pyrenees

3000 feet up, is one of the final Cathar strongholds: the Montsegur fortress. Bit of a hike, but well worth it.
http://en.wikipedia.org/wiki/Montsegur
For a little more on Cathar history, check out this New York Times article from April 2010:
http://travel.nytimes.com/2010/05/09/travel/09Languedoc.html?scp=2&sq=Cathar&st=cse