Croeso i'r Gymru Goosebal.
Now then... in Gower we have King Arthur's Stone aka Maen Ceti http://www.themodernantiquarian.com/site/111/maen_ceti.html
and Parc Le Breos http://www.themodernantiquarian.com/site/107/parc_le_breos.html
Both state that the nearest town is Llanelli but you'll have to row, swim or cross over Loughor Bridge to get to them as they're on the Swansea side of the estuary. :)
http://www.themodernantiquarian.com/site/3528/gower_peninsular.html

As far as Pembroke is concerned i'll give Wychburyman a shout for you as he's my 'man in the field' as it were.

Happy (and hopefully) dry holidays to you.

http://www.carmarthenshire-pages.co.uk/kidwelly/
http://www.pembrokeshire.co.uk/