We were staying in Nice and took a day trip to Cagnes Sur Mer specifically for Haut de Cagnes. The Bourg was beautiful and the views were awesome. I read that there was a museum in the castle at the top of the hill and assumed it was an historic museum of the castle and the area. Just know, it is not that. It's something of a modern art museum - not at all my style, but the 4 EUR entry fee is worth it to get to climb the tower and see 360 degrees of beautiful French landscape.