It's on the west Wales coast, close to Porthmadog (there's a vey pleasant steam train running from Porthmadog to Portmeirion, then a ten minute walk to the village). I'm no expert on PAtrick McGoohan's previous TV series,
Danger Man, but I'm pretty sure that an episode had been set in Portmeirion, leading to it's selection for
The Prisoner. The village is also used in an old Tom Baker
Doctor Who story,
The Masque of Mandragora, as well as various other one-off tv episodes and pop videos; most notably, XTC used it for 'The Man Who Sailed Around His Soul' (and Supergrass used it for their first single I believe. Wouldn't know about them though!).
I've just had a look; it's got it's own website here:
http://www.portmeirion-village.com/en/index.php.
Clough Williams Ellis was a really good sort; full of dreams for nice environments that were constructed but not entirely false or sharing a single characteristic. He wrote many books, notably one (pub. 1928) called
England and the Octopus - an early wake-up call to those who destroy our heritage. His vision for Portmeirion was to show that
built on his own private peninsula on the coast of Snowdonia where he built to show that the development of a naturally beautiful site need not lead to its defilement and that architectural good manners could be good business. His lifelong concern was with Architecture, Landscape Design, the protection of Rural Wales and Conservation generally.