I think the Moomin books are much more adult fiction, though they are usually marketed as for children. It is my theory that this is because they are illustrated, which would be rather silly, but we humans do have a tendency to stereotype things. As I said, I wasn't very fond of the books as a child, but find them really deep and beautiful when I read them as an adult.

Getting shown around any city by a native is usually the best way to see it, I think! That you also got to meet wiseheart makes it sound like an even better experience!