This is not just true in Denmark; the Rhine used to be incredibly polluted back in the 1980s, but now it&#x27;s pretty clean. The Amsterdam canals are a lot cleaner, though the inner city canals are not used for swimming, but I think that&#x27;s more an issue of facilities and awareness than of water quality. But in the eastern harbor area, kids love to swim.<p>The increased water quality is one of the big successes of increased environmental awareness that environmental organizations fought for in the 1980s.