Many of the buildings and structures in Govilon used locally quarried and dressed Old Red Sandstone. This material was excavated from a number of small quarries in the village. With the development of the canal quarries were developed alongside to enable the stone to be loaded straight onto canal barges. Some of these can still be seen when waling along the canal from Govilon to Llanfoist. A good example of this type of stone can be seen in the village War Memorial.
The Limestone Quarries were much more extensive. Limestone was a major raw material for the iron industry. From its earliest development in Blaenavon, quarrying on the mountain above Govilon commenced. Geological problems caused one of the earliest of the north-western quarries on the Blorenge, initiated c.1795, to be abandoned 1804
The large Tyla quarries on Mynydd Gilwern were the main source of Limestone rock for the Blaenavon works and stone was removed and transported to Blaenavon through the Pwlldu tunnel from the early 1800's to the 1920's. Further quarry excavations were developed below Pwlldu and on the Blorenge. The limestone quarry at Pwll Du is a scheduled ancient monument dating from the early 1800's. It is exceptionally well-preserved and contains an important water balance lift shaft which raised loaded limestone wagons to the tramroad. This quarry was operated by Walter Lewis to supply limekilns at Govilon and Llanfoist as well as the ironworks at Blaenavon and the forge at Garnddyrys.
All the quarries and associated features can still be visited with care to this day, as are the tramroads that served them. Water power was an important feature in the quarries. It was used extensively as a readily available counter-balance to lift trucks full of stone from the bottom of the quarries to the tramroads above. Water channels were dug across the mountainside to collect water and direct it into a number of ponds which are still evident today. From here water flowed into tanks, whose weight then lifted the stone. Water was also used to provide power in the forges and rolling mills. The reservoirs at Upper Pond and Lower Pond, which were both fed by Forge Pond (known locally as the Keepers Pond), served the Garnddyrys Forge. Only Forge pond still holds water with all the other ponds such as that supplied the water balance lift at Pwll Du quarry are now dry in all but the wettest of weather.
Millstone rock is another of the layers of sedimentary rocks that form the Blorenge Mountain. This material was used locally in milling operations. Cutting of the rock occurred across the summit of the mountain and evidence of this can be found.
