No visit to Budapest is really complete without a trip to wallow in the city’s famed art-nouveau pool. The Gellert Hotel and thermal spas were built in 1918 with an outdoor pool added in 1927 and then the indoor pool – its crowning glory – completed ten years later. Expect the odd band of older swimmers in aqua aerobic mode as the carbonic gases in the thermal waters promise to relieve blood-pressure and coronary disease. Outdoors a wave machine adds to the fun of the biggest pool. Saunas and massages can be picked up for an extra fee in the maze of parlours that connect to the pools.