The heart of the French town of Annecy might be its pretty old town, but its lungs are the lake. It’s here that local residents and visitors get outside and get active – running and cycling on lakeside paths, sailing and kayaking on the water or swimming in it. Or if that’s all too energetic you can just soak up the fresh air on one of the boat cruises that tour around the lake. Lake Annecy was formed by melting glaciers 18,000 years ago and the clear waters still flow in from surrounding Alpine rivers and springs. It’s surrounded by mountains with 24 small towns and villages scattered along its shores. There’s Menthon-Saint-Bernard with its castle built up on a rocky crag or Talloires with its abbey-turned-hotel. But I found my dream lakeside holiday spot at Château Ruphy, a mini castle built on a thin strip of land jutting out into the lake.