Can't believe this....guess their common in Europe. Emphasis on a balance between natural chemistry, living greenery, integration with the landscape, and a swimmable area. 1st link is a slideshow format. I gotta hand it to them for nice integration with the landscape, I just don't know if I'd want to swim in the murky water. Guess its like swimming in a lake.
http://www.thedailygreen.com/green-home ... ols-460908
Images from Google:
http://www.google.com/images?client=fir ... CDcQsAQwAw