Description

The monument comprises the remains of limestone quarry workings and a water-balance lift dating to the early 19th century. Pwll Du is an exceptionally well-preserved example of a 19th century limestone quarry that contains multiple features of importance. The most significant is the rare water-balance lift shaft in the S corner of the quarry, which raised loaded limestone wagons from the quarry floor to the tramroad at the top. The shaft is cut vertically through the limestone to a horizontal tunnel at the base that leads to the quarry floor. The upper section of the shaft comprises a stone built square structure built into the hillside. A roughly rectangular pond, 150m long and 25m wide, located to the S of the balance lift would have supplied it with water. The route of Hill's Tramroad, leading from Garn Ddyrys to Pwll Du, follows the top of the quarry, and a branch leads off it into the middle quarry levels. The base of the quarry contains complex patterns of spoil and the remains of several structures related to the working of the site. The quarry was already well-developed by 1819, with its face in a similar position to the present, but had closed by 1860. Ownership of the quarry was split between Walter Lewis and Lord Abergavenny, but it was operated by the Blaenavon Company.

The monument is of national importance for its potential to enhance our knowledge of quarrying in the industrial period. The quarry may be expected to contain archaeological information in regard to chronology, mining techniques and functional detail.

Source: Cadw