The Castle is the Clos Lucé where Leonardo da Vinci spent the last years of his life. The entire interior of the mansion can be visited. Despite the fact that entry is very expensive, it is well worth a visit. Access is quite well signposted, but far from the Royal Castle and up a fairly steep hill. Inside the house you can view the fully furnished rooms. The most interesting part however is the basement, where you can see lots of models of Leonardo's inventions, each with a card explaining its function. Some are even operational in order to illustrate the explanation. A replica of the famous Mona Lisa painting can be seen.