Twm Barlwm

A view of Twm Barlwm from the Croesyceiliog area of Cwmbran, with Cwmbran's Tower Block in the foreground, taken at dusk.

Twmbarlwm, also known as Twm 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. It commands extensive views across what is now the M4 corridor, over Newport & Cwmbran & out over the Bristol Channel.

At the top of the mountain, near its summit, are the remains of what is presumed to be an Iron Age hill fort, believed to have been built by the Silures, the Celtic tribe that inhabited the area before & during Roman times. There was also thereafter possibly a Roman signal point & a substantial Norman motte & bailey castle, which is incorporated into the eastern end of the fort, probably of early Norman construction.