The river seine, which carves its way through the heart of Paris has lifted a ban on bathing, which was in effect since 1923. This has been motivated of course by the sweltering heatwave which is eclipsing Europe at the moment.  Aside from Paris, many other major cities such as Copenhagen and Amsterdam actually encourage their locals to swim in their rivers.  

But not in Dublin, as many know the River Liffey is not exactly a hotspot for local swimming enthusiasts, but why is that?