The castle and it's location are even better than the photos. Marc was a very helpful and attentive host. The castle is perfectly comfortable and well-stocked. And although it has all the modern conveniences you still feel like you traveled back in time 1000 years. This was one of our best Airbnb experiences ever.
I definitely agree with the other commenters that it is essential/strongly recommended to bring all your food and water because there are no stores nearby.
Also bring good walking shoes for the climb up to the castle entrance and for exploring the surrounding area.