Gwerclas usually refers to a former castle and farmstead close to Cymmer

Cymmer

Cymmer is a small village in Neath Port Talbot in Wales, set on a hillside in the Afan Valley near the confluence of the River Afan and the River Corrwg. In 2001, Cymmer had a population of 2,883....

 in the parish of Llangar

Llangar

Llangar is a former civil parish in Denbighshire in Wales, south west of Corwen, its post town, and north east of Bala. It is situated at the confluence of the rivers Alwen and Dee, and includes the small hamlets of Bryn, Cymer, and Gwynodl. A large portion of the parish is barren. The village,...

 in the ancient cantref of Edeyrnion, Wales

Wales

Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

. It is now just an uninhabited upland area. The modest castle found at the site during the early Middle Ages

Middle Ages

The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

 is now completely ruinous. The ancient Barons of Cymmer

Cymmer

Cymmer is a small village in Neath Port Talbot in Wales, set on a hillside in the Afan Valley near the confluence of the River Afan and the River Corrwg. In 2001, Cymmer had a population of 2,883....

 yn Edeyrnion (known as the Hughes of Gwerclas

Hughes of Gwerclas

Hughes of Gwerclas were a native Welsh royal family descended from Owain Brogyntyn the illegitimate but acknowledged son of Madog ap Maredudd by a daughter of the "Maer du" or "black mayor" of Rûg in Edernion. His father granted to him and his successors the Cantref of Edeyrnion and the Lordship...

) cite this place as their ancestral home. Prior to the resettling of the castle in 1186 by the ancestors of the Hughes family it was the power base of the mysterious Maer Du or "Black Mayors" of Edeyrnion.