This monument comprises the remains of a group of structures on the sea-edge, the site of a 16th - early 17th century salthouse and fortified house. Used in the 19th century as oysterman's cottages, the site is divided into a series of three stone lined chambers at beach level, and a group of two storey buildings at higher level. The largest chamber produced on excavation the remains of a wooden pump, 1.75m long, comprising a hollowed out tree trunk with non-return valve. This is still in-situ. Sea water was fed into these chambers at high tide and pumped to the higher level to be evaporated in coal-fired furnaces to make salt. The buildings have possible musket loops.
The monument is of national importance for its potential to enhance our knowledge of early salt-making processes. Indeed, this saltworks represents the most intact example of its kind in south Wales. The monument retains significant archaeological potential and forms an important element in the wider south-Wales industrial landscape.
The area scheduled comprises the remains described and an area around them within which related evidence may be expected to survive.