The best cities in Europe for wild swimming

There’s something in the water – E.coli to be exact. After high levels of the bacteria were found in the Seine, questions were raised about how safe it would be for the triathletes and open-water swimmers taking part in the 2024 Olympic Games.

Meanwhile, just before the Oxford and Cambridge boat race in March, both teams were warned not to embrace the tradition of throwing the winning cox into the Thames: E.coli levels were 10 times higher than the measurement deemed ‘poor’ by the Environment Agency.

Elsewhere in Europe however, contamination has largely been falling for the last couple of decades. In general, it is now safe to go into the water. In its latest report published in June 2023, the European Environment Agency (EEA), which monitors more than 21,000 bathing sites across the continent (but no longer any in the UK), found that only 1.5 per cent had poor water quality.

Some lakes and rivers crisscross or hem the continent’s most beguiling cities, making a dip a viable part of a weekend break. The EEA has a handy map function on its website to help you discern the water quality of location before you take the plunge.

Below, we highlight five places that are perfect for wild swimming – and four you may wish to avoid.

Where to go wild swimming

Vienna, Austria

Austria came second only to Cyprus in the EEA’s latest rankings for water quality, while the Viennese authorities graded all of the city’s bathing sites as excellent during the 2023 season. At one popular city spot, they even claim that the water rivals the country’s “best lakes”.

Once a channel of the Danube river (until 19th-century water management turned it into a lake), the Alte Donau or Old Danube is so clear that you can see for up to four metres below its surface. Vegetation is carefully managed to act as a natural filtration system, keeping 20 species of fish happy, while motorised craft are banned.

In the summer months, outdoor swimming is as much a part of Vienna’s routine as the daily commute, with locals visiting the Old Danube to swim, sunbathe and sail before eating at one of the restaurants lining the shore. Others take the subway to Donauinsel (Danube Island) on the New Danube, with its volleyball courts, bars and 42kms of beaches.

Zurich, Switzerland

Bordering a shimmering lake and bisected by a meandering river, Zurich is built on the water – and the temptation to jump in is almost unavoidable. During the summer, 30 outdoor swimming venues open up and some locals even travel to work along the Limmat river, using the current to carry them to the centre of town.

This can be dangerous, however: visitors should stick to Zurich’s designated swimming baths – or to the lake, where all of the sites monitored by the EEA have been rated excellent.

Beside the well-heeled suburb of Seefeld, the towel-dotted lawns of Strandbad Tiefenbrunnen (entry around £7) lead straight to the water and make a good place to people-watch. Alternatively, for a more seaside-y feel, head for the sand at Strandbad Mythenquai, on the other side of the lake.

Bordeaux, France

Paris’s water may be a bit dirty, but another French city has turned its most popular bathing site bleu. In 2023, French authorities classified the water quality at Bordeaux’s Plage du Lac as excellent.

A 10-minute tram ride north of the centre, this sprawl of white sand bordering a manmade lake regained its Blue Flag status in 2023 too. With a lifeguard on duty between June and September, it’s great for families and has toilets and showers onsite.

Around an hours’ drive west, just before the balmy beaches near Arcachon, you’ll find the pine-backed lakes of   and Carcans, and just south of the Bay of Archachon, Biscarrosse and Sanguinet, all of which were rated ‘Excellent’ by the EEA.

Berlin, Germany

It may have a reputation for clubs and cabaret but Berlin also comes with one of Europe’s most wholesome wild swimming scenes, centred on the local region’s 3,000 lakes. Even at the swimming areas nearest to the city, the water is rated excellent by the EEA. Make for the un-touristy Strandbad Plötzensee (£7) where the hipsters hang out, Strandbad Weissensee with its sandy beach (£7) and Strandbad Orankesee (£6.85), with its kid-friendly twirly waterslide into the water.

Meanwhile, around 25 minutes to the west of Berlin by S-Bahn train, Strandbad Wannsee’s sandy beach stretches for more than 1,250m along the lake of the same name.

If you’re prepared to venture a little further, the S-Bahn takes 45 minutes to reach Potsdam, the former playground of the Prussian elite which is home to 16 grand palaces dotted throughout forested parkland. The lakes here, such as Schlachtensee, are popular with Berliners come summer.

Granada, Spain

Granada is far enough from the coast to make lake and reservoir swimming a popular pursuit, and its surrounds have some brilliant places to dip your toes in the water – if you’re prepared for a bit of an adventure. Around 40 minutes’ drive south west, Los Bermejales reservoir has an impeccable EEA record, and comes with Caribbean-blue waters, pine-scented air and (unlike the Cubillas reservoir nearer the city, where currents can be very dangerous and it’s best to stick to organised watersports), a shallow bathing area with a beach restaurant attached to a campsite.

Meanwhile, although it’s not rated by the EEA, the river pool near Restaurante Maitena on the outskirts of Güejar-Sierra is also a popular bathing spot, busy with paddlers and dunkers in summer. A 30-minute bus ride from central Granada, the river pool in this hill town is fed by the run-off from the Sierra Nevada mountain range.

And the cities to avoid

Brussels, Belgium

When the sewers overflow in this city, the waste goes straight into its canal, according to the campaigning organisation Canal It Up, which also notes that plastic and dead rats float upon its surface. Nobody would want a dip in this waterway – or the equally polluted River Senne – which may explain why Brussels hasn’t embraced al fresco swimming: there’s currently only one public outdoor pool in the city.

Naples, Italy

The Sarno is regularly labelled Europe’s most polluted river thanks to being the recipient of both agricultural waste and insufficiently treated wastewater – and it flows straight into the Med just south of Naples at Rovigliano. In 2023, when campaigning organisation Goletta Verde analysed water in the city, it found three particularly heavily polluted points, including the beach in the seaside suburb of San Giovanni a Teduccio.

Rotterdam, the Netherlands

One of only two countries monitored by the EEA to be rated ‘poor’ at three per cent or more of its sites, the Netherlands has banned swimming in three recreational lakes in South Holland for 2024,  including one in Rotterdam. It’s due to contamination from toxic PFAs (chemicals used to make non-coatings, packaging, adhesives and electrical insulation).

Paris, France

Paris Mayor Anne Hidalgo has made it her mission to open three bathing sites along the Seine to ordinary (non-Olympic) swimmers from 2025 and she’s even pledged to wade in herself before the Games, echoing a promise made by Jacques Chirac. A clean-up operation focusing on improved wastewater disposal is underway, but whether her dream becomes a reality remains to be seen.