Twmbarlwm also known as Twm Barlwm, Twyn Barlwm, or locally known as "The twmp" (translation: hump) or the Pimple because of the mound that lies at its summit, is a mountain situated 2 km (1.2 mi) to the northeast of Risca in South Wales. It is 419 m (1,375 ft) high and is a well known landmark throughout the region.