Warren Hill Fort is in close proximity to the Briton Ferry bridge. It was first discovered to be the site of an Iron Age Hillfort during excavations for the laying of a water pipe in 1971. The ridges that can be seen are the ramparts of the fort. In the Nineteenth Century a watch tower was built on it as a look-out for ships waiting in the bay for an escort into the port. In the past, bon-fires were built on top of the hill during celebrations such as Jubilee celebrations for King George V. During the Second World War a concrete pill-box was built on the hill in order to spot enemy planes.

Gaer Fawr is the site of an Iron Age fort overlooking the River Neath above Baglan and Briton Ferry. The site consists of an oval enclosure on the northern slope of Mynydd y Gaer. Complex concentric banks form an enclosure, with 5 cairns amongst the defenses.

Situated close to Gaer Fawr, Buarth-y- Gaer is also the site of an Iron Age hillfort some 100m across, with a Bronze Age burial cairn inside, at the highest point of Mynydd-y-Gaer.

In the school playground of Ysgol Carreg Hir is The Carreg Hir ('long stone'), a standing stone probably dating to the Bronze Age, 9 ft 2 in (2.8 m) high, 5 ft 7 in (1.7 m) wide and about 2 ft (0.6 m) thick. The stone was set into a concrete plinth in recent times, though it is believed to be in its original location. Archaeologists think that it may once have stood upon a mound, overlooking the River Neath. It is a Scheduled Monument.

There is a published 1848 reference to this stone in which it says that "there is a charm, not yet discovered, which can compel [the stone] to speak, and for once to reveal the secret of its history: but that having once spoken it will be silent forever." Another legend says that there is an underground passage leading between the stone and Neath Abbey some 1.3 miles (2.1 km) to the North; the stone is said to be aligned upon.

This mile marker from 1841 at the height of the industrial expansion of Melin Cryddan is situated on the main road. The Romans laid good metalled roads to move soldiers and supplies quickly across their Empire: they measured distance to aid timing and efficiency, possibly marking every thousandth double-step with a large cylindrical stone. 117 still survive in the UK. The Latin for thousand was ‘mille’ and the distance was 1618 yards; the eventual British standard mile was 1760 yards, although ‘long’ miles also existed into the 19th century.

After Roman times, roads developed to meet local community needs: in 1555, an Act of Parliament made local parishes responsible for their upkeep and boundary markers became important.

From the 1840s, rail travel overtook road for longer journeys. In 1888, the new County Councils were given responsibility for main roads and rural district councils for minor routes. As faster motorised transport developed, the importance of the milestones decreased.

‘Milestone’ is a generic term, including mileposts made of cast iron. Such mile markers are fast disappearing; around 9000 are thought to survive in the UK. Most were removed or defaced in World War II to baffle potential German invaders and not all were replaced afterwards. Many have been demolished as roads have been widened, or have been victims of collision damage.

Nowadays, roadside milestones generally fall within the remit of the local Highways Authority or the Highways Agency and their contractors.