The Château Grimaldi is the fortified medieval castle that anchors Haut-de-Cagnes, the hilltop village at the top of the town. Built by Rainier I of Grimaldi (ancestor of the Monegasque royal family) in the 14th century, it was enlarged and embellished in the 17th century, and today houses the Musée d'Art Moderne Méditerranéen — a rotating collection of 20th-century works donated by artists connected to the Côte d'Azur.
The collection itself is modest but the building is exceptional: climbing through the medieval towers and galleries to reach the upper floors, you get a succession of spectacular views over the coast from Nice to Antibes. The top-floor reception room, with its baroque trompe l'oeil ceiling, is particularly striking. Combined with a walk through Haut-de-Cagnes' medieval lanes, this makes for an excellent half-day visit.