The entry is about 4€/adult. There is access to one part of the castle inside, where you can read about the history. Majority of the castle to the left however is not accessible. There are some benches inside and outside for you to rest on. The view is great, if a little damaged by the motorway being built underneath. There should also be a dirt path outside the castle that will take you around it, and the views should be great. It started to rain for us, so we didn’t manage to do that bit