The Parc is closed for tourists. You need to be a university students for access. I don't know when was closed for tourists.
Although the castle and the lake are beautiful, I can not recommend for sightseeing as for security reasons access for the public is closed.
The Parcel is lovely. Access is restricted to students and personal of the University of Nice. This is vigorously controlled.
Chateau and Park Valrose lay inside the campus of University of Nice Sophia Antipolis. It's a beautiful place with a chateau, park, and a pond with some water birds strolling around. Well worth a visi...