Depends on what you want to shoot. Landscapes I assume. Sandymouth Bay and Crackington Haven on the North Cornwall coast (near Bude) are nice, especially around sunset. Unfortunately Penzance is right the other end of the county.....its far enough to be a pain. In reality though, the whole of Cornwall is bit of a haven. Check out this website for some inspiration, then Google Map the location.
http://www.themagicofcornwall.com/pages/gallery.htm
As for places around Swansea, its the gateway to the Gower Peninsula. Not been there myself, but you can head a little further west to Laugharne, Tenby, St Davids, Solva; all places in the Pembrokeshire Heritage Coastline (I think). All less than an hour's drive from Swansea. Haven't been to North Wales for years - at least not with a decent camera.
Just pray the weather next July is better than the one just gone.....