Llansteffan Castle (Cadw)

This headland castle overlooking the green farmlands, swirling sea and gleaming sands of the Tywi Estuary and Carmarthen Bay, boasts one of the most stunning locations in Wales. That’s not to say that the stronghold itself is lacking in interest. Llansteffan, which controlled an important river crossing, occupies a site that has been defended since prehistoric times.
Its rough stone walls, dating from the late 12th century, enclose an Iron Age promontory fort occupied in 600 BC. Although ruined, the castle retains its power to intimidate – especially when you approach its massive twin-towered gatehouse, built in around 1280 and still looming large.