The village features substantial remains of a Norman castle and the adjacent Cwm George was the site of the celtic hill fort from which the village takes its name. The hill fort site was excavated by Leslie Alcock of University College, Cardiff between 1954 and 1958 and was found to contain evidence of major wooden structures and a large quantity of high-status metalwork and jewellery. There were also glass items and imported pottery dating from the sub-Roman period of between the 5th and 7th centuries. The castle was originally the seat of a Norman noble called Baron de Sumeri or , but the structure went into decline around 1322 when the de Sumeri male family line came to an end.