The River Liffey is quite a narrow river dividing
Dublin into roughly equal North-South sections. However at low tide on sunny days (don't worry: a rare occurence), the smell is quite
obnoxious crossing over some of the bridges. Fortunately as a tourist you won't actually notice this as long as you're paying attention to the
beautiful architecture surrounding it (
sarcasm only half-intended).
The Liffey has been the site of many failed government schemes over the past number of years. The Millennium Clock was supposed to be a digital clock that would float in the river and count down the seconds until the year 2000. It was placed around 1998 at a cost of £500,000 or so IIRC, and was removed a few short months later after the slime from the river accumulated to such an extent that it obviously proved uneconomical to continually scrape the stuff off. Earned the title "The Time in the Slime".
More recently, the Liffey 'boardwalk' was constructed, a horribly artifical and in no way romantic/peaceful/serene set of plastic wood-coloured boards that run alongside the river for about 200 yards (where the pavement is dangerously narrow), again built at some obscene cost.
I could think of other 'projects' but these will have to do for now. Don't let this writeup in any way put you off visiting Ireland, however. Just be aware that the Liffey is not always romantic, fresh, vivid, or any of the words you might have heard describing it.