Dinefwr Castle (also known as Old Dynevor Castle) is a ruined castle overlooking the River Towy near the town of Llandeilo, Carmarthenshire, Wales. It lies on a ridge on the northern bank of the Towy, with a steep drop of one hundred feet to the river. Dinefwr was the chief seat of the Dinefwr dynasty of the Kingdom of Deheubarth. The castle is a Grade I listed building. Description The present castle is entered via a fortified entrance protected by a restored length of battlement. The short path from the car park gives an extensive view of the Towy valley. The door admits the visitor to the main space enclosed by the walls, from which there are several stairs to the main battlements and towers. A narrow spiral staircase leads to a high tower, which gives extensive views of the deer park to the north and the Towy valley to the south and west. The castle keep is entered via the cellar at its base, but access to the circular walkway at the top can only be made via the battlement walk. Details such as the well and several garderobes are visible in the structure. There is a path around the base of the main structure to the north. History Tradition relates that a castle was first constructed on this site by Rhodri the Great, but no archaeological remains have been dated from this period. Dinefwr later became the chief seat of Rhodri's grandson Hywel Dda, first ruler of Deheubarth and later king of most of Wales. Rhys ap Gruffydd, ruler of Deheubarth from 1155 to 1197, is thought to have rebuilt the castle. Giraldus Cambrensis tells a story about a plan by King Henry II of England to assault the castle during a campaign against Rhys. One of Henry's most trusted followers was sent on reconnaissance, guided by a local Welsh cleric, who was asked to lead him to the castle by the easiest route, but instead took the most difficult route he could find, ending the performance by stopping to eat grass with the explanation that this was the diet of the local people in times of hardship. The planned attack was duly abandoned. Rhys ap Gruffydd also built the spectacular castle at Carreg Cennen, about four miles away to the south. It is not visible from Dynefwr, but Dryslwyn Castle can just be seen on a hill