Of the 18 kilometers of gravel, you probably need short but quite steep vehicles, 14% of them have, from what I remember. The journey is a dream, although it is terribly long at the end. It is much longer when we count from the entrance to the park to the exit, as I was driving. It will be over 20 km. When I was driving, there was a plague of midges, I was completely black from them. Fortunately, they don't bite, they just sit. Overall, I recommend it.