Cagnes-sur-Mer, Antibes, and Nice
As I found out while perusing Google Maps, the French Riviera is a real hotspot for the visual arts. The area boasts a museum each dedicated to Matisse, Chagall, Renoir, and Léger, and two dedicated to Picasso. Choosing between them was difficult, but we eventually decided to see Renoir in Cagnes-sur-Mer, as the city is easily reachable by train, and we had not been there yet.