I can see this out of the window and have been atop it.
Twmbarlwm, also known as Twm Barlwm, Twyn Barlwm or locally known as "the Twmp" (translation: hump), the Nipple or the Pimple because of the mound that lies at its summit, is a hill situated 2 km (1.2 mi) to the northeast of Risca in South Wales. It is often mistakenly referred to as a mountain but is actually a hill due to being under 600 m (2,000 ft). It is 419 m (1,375 ft) high and is a well-known landmark throughout the region. It commands extensive views across what is now the M4 corridor, over Newport and Cwmbran - with part of it coming into Cwmbran - and out over the Bristol Channel
TwTwmbzrlwmmbarlwTwmbarlwmm (or The Twmp) near Cwmcarn is 500 metres above sea level with glorious views of the Severn Estuary. Packed with history and folklore, it sits at the end of Mynydd Henllys (‘Old Court Mountain’) ridge, which probably refers to a Llys (‘Court’) located in the Iron Age hillfort before the Norman motte and bailey castle was built. Head to the Early Bronze Age cairn, near the summit and the motte, where a buried giant (possibly the body of Bran from the Mabinogian ogion) and some buried treasure are supposedly guarded by a swarm of bees. In fact – during the 1860s, a huge swarm of battling bees and wasps was reported above Twmbarlwm. Strange and alluring subterranean music is sometimes heard emanating from the hill.