The old mountain called the « Massif Central » was raised again when the nees an the Alps wre created. It bears various names depending on the area, and is called « Montagne Noire » on its South border. It is made by rolling hills, getting lower and lower towards the plain where Carcassonne was built, as a latch between Toulouse and the Mediteranean.
These hills offer poor soil and hot weather, and are covered mainly with evergreen oaks and « garrigue ». There were built in medieval times the Cathare castles of Lastours.