Riehen Natural Swimming Pool

Naturbad Riehen is an outdoor public pool in Riehen, the municipality on the northern edge of Basel, close to the German border. It is known for two things: its architecture, which comes from the Basel firm Herzog & de Meuron, and its method of keeping the water clean. Instead of adding chlorine, it uses a natural filtration system based on plants and gravel, a design approach that was unusual when it was built and that remains a point of local pride. The architects are famous for projects around the world, but this is a modest, low-lying structure that blends into the landscape.

The idea of a natural pool is to treat water biologically. Water circulates through zones with plants and fine gravel, where microorganisms and plant roots remove nutrients and impurities, and the clean water flows back into the swimming area. The result is water that feels softer on the skin than a chemically treated pool, with no chlorine smell, and many swimmers find it more pleasant for long stays. Because the system depends on natural processes, water clarity can change with weather, and on very hot days or after heavy rain the pool may look a little different from a conventional one.

The setting is simple and green. Wide lawns surround the pool basins, with trees at the edges for shade, and visitors spread out towels and picnic on the grass. There are shallow areas for small children, and deeper sections for those who want to swim lengths or dive. Changing rooms, showers and a small kiosk are available, as in most Swiss public pools. Shade is limited on the open lawns, so hats and sun cream are sensible, and the pool is at its busiest on hot weekends. If you want a quieter experience, go early in the morning or on a weekday.

The pool belongs to a long Swiss tradition of public open-air baths, called Badi, which are a social centre in summer for families, teenagers and older residents alike. Riehen's version combines that tradition with a modern design idea, and it makes a good contrast with the cultural stops in the area. Fondation Beyeler is not far away, and the Wenkenhof gardens and the Museum Kultur & Spiel are also close by, so a swim can be part of a day that includes art and a walk.

The pool is reached by tram or bus from Basel, and the journey from the city centre takes a short time. Because it operates as a seasonal outdoor facility, it is open only in the warmer months, and opening dates, hours and ticket prices should be checked on the municipality's website before you go. It suits families, swimmers who prefer chlorine-free water and visitors interested in contemporary architecture. Allow a half day if you want to swim and relax, or an hour if you simply want to see the building and its surroundings.