The Chateau d'If is worth a visit. It takes a short speedboat ride from Marseille Port, and the return boat is also on time. The entire castle is full of legends because of Alexandre Dumas's description. This has a clear orientation in the visiting experience. In addition to introducing the military, political and cultural overview, the castle also marks the cells where the characters in the novel were imprisoned. At the same time, there is an introduction to the surrounding ecology and an island chronicle on the island. If you go there in the off-season, there are very few people, and you will usually finish the tour quickly. This kind of place really needs to be prepared in advance to find the fun, otherwise it will become a one-time visit.