Details

The monument includes a 16th century forge, dam and slag heaps surviving as earthworks and below-ground remains. It is situated at the foot of a stream valley, north of Marden's Hill in Ashdown Forest on the High Weald.
The dam is orientated east-west across the valley floor. It is about 90m long and about 3m high and is breached by the stream 35m from the west end. A section of the dam, where breached, shows that it has twice been raised. There is a spillway at the east end. The iron working area is in the locality of the stream. The remains of the forge are preserved in the stream bed, downstream from the dam, where the circular wooden base of an anvil block with associated planking has been identified. Forge cinder has been observed in and around the stream.
Crowborough Forge is also known as Grubsbars. It is referred to in 1593 when it was owned by William Bassett of Withyham. The site of Crowborough Warren Furnace, which the forge may have been worked in conjunction with, is a separate scheduled monument about 550m upstream.
The monument excludes all modern fences and fence posts, gates and gate posts, but the ground beneath these features is included.

Sources: East Sussex HER MES5103. NMR TQ43SE17. PastScape 407093.
Crossley, D. 1991. English Heritage Monuments Protection Programme. Industrial Monuments: The Iron and Steel Industries. Step 3 report. Version O (Site Assessment 55).
2008. Wealden Iron Research Group. Iron Site Database. www.wirg.data.org [accessed 01-June-2009]

Source: Historic England

Reasons for Scheduling

Iron has been produced in England from at least 500 BC. The iron industry, spurred on by a succession of technological developments, has played a major part in the history of the country, its production and overall importance peaking with the Industrial Revolution. Iron ores occur in a variety of forms across England, giving rise to several different extraction techniques and structures. Ore was originally smelted into iron in small, relatively low-temperature furnaces known as bloomeries. These were replaced from the 16th century by blast furnaces, which were larger and operated at a higher temperature to produce molten metal for cast iron. Cast iron is brittle, and to convert it into malleable wrought iron or steel it needs to be remelted. This was originally conducted in an open hearth in a finery forge, but technological developments, especially with steel production, gave rise to more sophisticated types of furnaces.
Crowborough Forge and its associated archaeological features survive well. The site has been largely undisturbed and as such holds a high degree of archaeological potential. The forge structure will survive as buried remains either side of the present stream. The forge probably had a short life-span and the buried remains are likely to provide closely-datable evidence. It has group value with Crowborough Warren Furnace, a short distance upstream.

Source: Historic England