St David's is the smallest city in Wales and the UK due to it's impressive Cathedral. St David founded a monastry at this location in the 6th Century. The city has lots to offer, especially considering it only has about 2000 residents, and is becoming something of a centre for arts and crafts.
http://www.stdavidscathedral.org.uk/tours.htm

http://www.haverfordwest-wales.info/vis_home.asp