Thermen Barendrecht is a boutique wellness resort just south of Rotterdam whose saunas are each themed on a famous painting, from Botticelli's Venus in the infrared cabin to Van Gogh in the meditation sauna. There are seven saunas plus a steam bath, Aufguss sessions in the Kelo sauna, a birch-whisk banya ritual, indoor and outdoor pools, whirlpools and a plunge bath. There are no swimwear days. Day entry from €52; open daily 10:00 to 22:30.