Dinefwr Castle (sometimes anglicized as Dynevor) is a Welsh castle overlooking the River Tywi near the town of Llandeilo, Carmarthenshire, Wales. It lies on a ridge on the northern bank of the Tywi, with a steep drop of one hundred feet to the river. Dinefwr was the chief seat of the Principality of Deheubarth. The castle is owned by the Wildlife Trust of South and West Wales (who do not charge for entry) and is managed by Cadw but lies within Dinefwr Park, which is owned by the National Trust. Visitors who wish to see the castle and are driving there, may pay admission for the car park, if not National Trust or Wildlife Trust of South and West Wales members. A separate fee is payable if you wish to visit Newton House. Alternatively, access is free to walkers from Llandeilo town nearby, an