I have found sites listing the address as at Frederick St (that building was knocked down over two years ago), and John St (we have now closed, and are in the process of moving). I have tried to inform ones that offer the option to update their info. It's not really my job, I know, but since Google Maps has spent the last two years sending Central Library visitors, using SatNav, to a private address down the bay, I figure every little helps!
Cardiff Central Library
Cardiff CF10 1FL
I did notice that The Sprout had a little piece about it, which at least offers a tease of what we have to offer.
Swansea Library seem to have their own blog, although I can't quite tell if there really is someone called Paige Turner, or whether that name hides a sinister cabal of subversive staff (?) Last year, when they opened their own new Central Library they had pictures of work-in-progress, video clips, etc. (sigh).
And then again, when a library gets built because the tax-payers actually wanted the upgrade, you can end up with the astonishing Seattle Library, or the one in Minneapolis (entry from Wikipedia), whose budgets make Cardiff's look miniscule, I suppose. Although, to be fair, those two do get listed as America's Most Literate Cities.
Seattle has maybe twice the population of Cardiff, but when consulted directly, in 1998, the public gave 69% approval to spending $196 million to upgrade the city's library service. A large chunk of it went towards the award-winning Central Library (Wikipedia entry). And yes, they are a wealthy city (dot.coms, internet, computers, etc).
Minneapolis, who consulted its citizens in 2000, got voted a $140 million package to similarly improve their services. Their population is not a lot bigger than Cardiff's. Their new Central Library opened in May 2006.