Spas with reservation required in Germany

Bad Wörishofen, Bavaria

Adults-only thermal baths in Bad Wörishofen with palm-house pools, mineral pools and saunas; day passes available, minimum age 16.

Aachen, North Rhine-Westphalia

A suite hotel in central Aachen where each private room has its own jacuzzi and sauna, booked by the night rather than a day pass.