[refactor_master]

Swimming in the Copenhagen harbor (Denmark) is also possible

https://www.visitcopenhagen.com/copenhagen/activities/baths-...

It might have a slight upper hand in cleanliness with being directly connected to the sea.

[harry8]

Swimming in Sydney Harbour is also possible. They did it for a leg of the triathalon in the olympics a couple of decades back. Wouldn't recommend though, there's a lot of bull sharks in there and they're kinda aggressive. Netted beaches and bays are the go.

[lmpdev]

Only ~1,000km north, bullsharks have been filmed swimming in groups of ~150 near the Story Bridge in the Brisbane River

To any tourists visiting Aus, please only ever swim where locals swim and only between the flags if on the coast

[mcv]

I live in the eastern docklands of Amsterdam, and there's always lots of swimming here. Amsterdam has invested a lot in cleaning up its canals and other waterways and water quality has improved a lot over the past couple of decades. And there's no sharks.

[dredmorbius]

Or the North Sydney pool, when it re-opens, with luck next month.

Not open water, but salt, and an absolutely gorgeous location.

[tokai]

Clean as long as you don't disturb all the mercury in the top layer of the bed.

[cs02rm0]

I saw that, a bit further along from Kastrup sea bath, with the planes coming in to land at the airport.

I guess it's open water unlike the Seine, but it did surprise me, I felt like I was sat in quite an industrial area when a couple walked past in swimming costumes and towels.

[vasco]

The canals in Copenhagen are pristine compared to cities like Amsterdam. I'd dip in there any time!

[stevesimmons]

People swim in the canal opposite my Amsterdam office every day!

[mcv]

In the 1990s, water quality in Amsterdam was pretty bad, but it's improved enormously since then. I live in the eastern docklands area and people swim a lot in the old harbour.

[kristiandupont]

I go in every morning. Massive quality of life factor, that!