When I visit the south of France in July, I plan to base myself in Nice and do a few daytrips to places like Cannes, Monaco, St Tropez. I am travelling alone and will probably only want to take a daypack for these trips. For arguments sakes, if I wanted to go to the beach at one of these places, what would be the chance of finding a locker in a train station or the like, to keep my stuff safe? Is anyone aware of public lockers in these specific places? I won’t be staying overnight in these places so I assume using hostel lockers is out of the question?

While I’m asking this question, does anyone know if lockers are available in Spain in towns like Sitges, Cadaques etc.?