We recently spent 3 nights over Easter (a few miles from Pembrey County Park) in Carmarthenshire, West Wales at a cottage called Mountain Lodge. This restored cottage can be found on the Holiday Lettings site and it is also reviewd on Tripadvisor.
It has a mezzanine level with a secret doorway which our grandson used continuously! The views from the back for are stunning. One can see the Gower peninsular and Worm’s Head from the back door. The cottage itself has a log burner and underfloor heating and sleeps 4 but has a cot etc for a baby and extra mattress for a toddler. We were blessed with lovely weather. It is a perfect retreat for a few days!