Dinefwr Castle, a mediaeval castle of Welsh princes, remains of Roman forts, and Newton House, a mid-seventeenth century mansion, designed for George Rice (1724–1779) and his wife Lady Cecil Talbot (1735–1793), Baroness Dynevor are set in glorious parkland. The house was encased in stone in 1858 by Richard Kyrke Penson (d.1886) in a bastard neo-Jacobean-cum-neo-Gothic style, with the addition of four corner towers with pyramidal slate roofs.
In the house are two interesting pairs of pioneering country-house views, by different hands, of the early eighteenth-century British (Welsh) School. Among the portraits, accepted in lieu of tax in 1997, from Richard Charles Uryan Rhys (1935–2008), 9th Baron Dynevor, with the aid of the National Heritage Memorial Fund, that also remain, of particular interest, is that of a friend and neighbour, 'Thomas Keymer of Kidwelly (1722–1784), à la Chinoise' by Gavin Hamilton in 1754. And an individual bequest of 'Mary Queen of Scots Bidding Farewell to France, 1561', 1893 by William Powell Frith (1819–1909) is notable.