The Château de Chillon is the unmissable sight of the Lake Geneva region — a medieval castle perched on a rocky island in the lake, three kilometres south of Montreux. It's one of the best-preserved medieval castles in Europe and the most visited historic building in Switzerland, and the combination of dramatic lakeside location, well-maintained interiors, and genuine historical depth makes it entirely worth the crowds.
The castle was built and expanded between the 10th and 13th centuries by the Counts of Savoy, who used it to control the road along the lake. The underground dungeons, the great hall with its painted wooden ceiling, the bishop's chapel, and the towers with views across the water to the French Alps are all part of the self-guided tour. The walk south from Montreux along the lakefront promenade takes about 45 minutes; the road hugs the water the entire way and the castle comes into view dramatically as you round the final headland. Open daily; entry around 14 CHF.