Penlle'r Castell is an historic ruin on the summit of Mynydd y Betws in the far north of the City and County of Swansea. The Penlle'r Castell site was probably a late 13th-century stronghold garrisoned by one of the Marcher Lords.
Penlle'r castell is located 1213 feet above sea level.[1] The meaning of the name in English is "summit of the place of the castle".