Spend a night by the River Thames in Greenwich -- 20 minutes by rail from central London -- for 53% less than usual this summer. Dinner, bed and breakfast stays at De Vere Devonport House are now £119, and include a bottle of sparkling wine.

The 4-star hotel occupies a collection of historic former Naval buildings, and is part of the Maritime Greenwich UNESCO World Heritage Site, which includes the Old Royal Naval College, the Royal Observatory and Cutty Sark.