The National Eisteddfod is a large annual festival celebrating Welsh language culture. I takes place during the first full week of August a different venue every year, alternating between north and south Wales. In 2008 it is Cardiff's turn to host the Eisteddfod (between 2-9 of August), and unlike other Eisteddfods which take place on large out of town sites in the countryside, this one will be in the middle of the capital city.
On the 'Maes' (main site), there are competitions and demonstrations for singing, traditional dancing, traditional instruments, poetry, drama. There are also fringe event taking place on and off the Maes, like gigs (at Cardiff Student Union Hall, Clwb Ifor Bach (http://www.qype.co.uk/place/89592-Clwb-Ifor-Bach-Cardiff) and other smaller venues TBC).
Great efforts are taken to make the festival accessible to those who do not speak Welsh, or who are not fluent, with simultaneous translation available for major ceremonies and competitions, and any army of helpers around the Maes in red t-shirts with 'Here to Help' written on them. There's a special tent called Maes-D which give information on learning Welsh.
There's a large art and craft tent (when I say tent, I mean a massive temporary structure), that shows different types of work from paintings, to sculptures and installations.
In the last two years, bars selling alcohol have been added to the Maes (despite much resistance from non-comformists!), and there's nothing better than being in the bar areas on the last Saturday afternoon when members of all the male voice choirs congregate after their competition and down a few pints before bursting into song again.
I'll add more info here as more events are confirmed. read more