Pwllheli is the traditional market-town of the beautiful Lleyn Peninsula(or in Welsh, Pen Llyn). The town is on the coast, with two sandy
beaches (though the better beaches lie further down the lleyn, for example; Quarry a busy sandy beach, Hell's Mouth (Porth Neigwl in Welsh) a famous surfing beach and remote tranquil beaches like Porth Ysgo which has a 20' waterfall), a marina host to many Sailing regattas and as the market town has shops and cafés.
To find out more look at these sites:
http://www.llyn-wales.co.uk (on the Lleyn)
www.penllyn.com (on the whole of the lleyn)
http://www.britinfo.net/index_Pwllheli.htm (more commercial)
http://hen.gwynedd.gov.uk/adrannau/economaidd/busnesmarchnata/pwllheli/croeso/index.english.html (a biased account by Gwynedd council of Pwllheli and surrounding area)