The benefits of Yverdon water have been known for over 15 centuries, since the Romans set up camp in the spa town. The water's extremely high sulphuric content makes it ideal for treating rheumatism, skin disorders or simply for a relaxing soak. The sulphur also means the water should not be drunk and lends it a particular odour reminiscent of rotten eggs - although this tends to fade as one gets used to it.

The baths consist of an indoor and two outdoor pools, the latter being preferable due to the added bonus of a prime view over the Jura and Alps. A swimming bath with a strong current remains between 28 and 32 degrees Celsius, while the more agreable relaxing bath is heated to 34 degrees. Added delights include a selection of underwater massage jets, a shoulder-massaging spray and a jacuzzi section. Don't hog your favourite jet - a flashing light goes off every three minutes to move bathers onto the next one and jet protocol is important - don't even think about doing them counter-clockwise!

Although the baths are open all year round, the hot water can be a little unpleasant in the summer. It is far more romantic to wade in the winter, as steam rises around you and snowflakes fall onto your (mandatory) swimming hat.