La Roche Guyon is built right into the limestone cliffs and from the front is amazing, but has only been spartanly restored. Much more work is required to give it the elegance it once had. Not really worth touring, except for the fact that Field Marshall Erwin Rommel made it his headquarters to defend Europe from the Allied invasion of Normandy. You can walk into the empty bunkers he had built into the hillside. The castle, too, was part of the defense against English incursion into France in the Middle Ages.
The history of the castle is here: <https://en.wikipedia.org/wiki/La_Roche-Guyon>.
