Top 10 sightseeing in the United Kingdom #10. The Lake District National Park of England Area -- 2,292 km2 Largest lakes 1. Windermere - 14.8 km2 2. Ullswater - 8.9 km2 3. Derwentwater - 5.5 km2 4. Bassenthwaite Lake - 5.3 km2 5. Coniston Water - 4.0 km2 Highest mountains 1.