Scowles are landscape features which range from amorphous shallow pits to irregular labyrinthine

Labyrinth

In Greek mythology, the Labyrinth was an elaborate structure designed and built by the legendary artificer Daedalus for King Minos of Crete at Knossos...

 hollows up to several metres deep and are believed to be almost unique to the Forest of Dean

Forest of Dean

The Forest of Dean is a geographical, historical and cultural region in the western part of the county of Gloucestershire, England. The forest is a roughly triangular plateau bounded by the River Wye to the west and north, the River Severn to the south, and the City of Gloucester to the east.The...

 in Gloucestershire

Gloucestershire

Gloucestershire is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn, and the entire Forest of Dean....

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

.

They have traditionally been interpreted as the remains of prehistoric and early historic open-cast iron ore extraction, but investigation undertaken by the Forest of Dean Archaeological Survey from 2003 to 2004 suggests that they have a primarily natural origin which has been exploited by humans.

Origin

Scowles have developed over millions of years. They occur in a broken ring around the central part of the Forest of Dean, and are confined to particular geological outcrops of carboniferous limestone

Carboniferous limestone

Carboniferous Limestone is a term used to describe a variety of different types of limestone occurring widely across Great Britain and Ireland which were deposited during the Dinantian epoch of the Carboniferous period. They were formed between 363 and 325 million years ago...

 and sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

. Ancient cave systems were formed underground, before iron-rich water from the coal measures

Coal Measures

The Coal Measures is a lithostratigraphical term for the coal-bearing part of the Upper Carboniferous System. It represents the remains of fluvio-deltaic sediment, and consists mainly of clastic rocks interstratified with the beds of coal...

 of the central Forest area permeated from the surface and deposited iron ore in crevices. The caves were then uplifted

Tectonic uplift

Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...

, eroded and exposed as a surface of deep hollows and exposed rock.

Much later, humans — certainly from the Iron Age

Iron Age

The Iron Age is the archaeological period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing...

 and later in the Roman

Roman Empire

The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....

 period — recognised that iron ore could be found in veins and pockets in the exposed rock faces. In some places, when the surface exposures were exhausted they followed veins of iron ore underground. The ore was then smelted locally, using locally obtained charcoal

Charcoal

Charcoal is the dark grey residue consisting of carbon, and any remaining ash, obtained by removing water and other volatile constituents from animal and vegetation substances. Charcoal is usually produced by slow pyrolysis, the heating of wood or other substances in the absence of oxygen...

, and made into useful objects or traded, by way of the River Wye

River Wye

The River Wye is the fifth-longest river in the UK and for parts of its length forms part of the border between England and Wales. It is important for nature conservation and recreation.-Description:...

 or ports on the River Severn

River Severn

The River Severn is the longest river in Great Britain, at about , but the second longest on the British Isles, behind the River Shannon. It rises at an altitude of on Plynlimon, Ceredigion near Llanidloes, Powys, in the Cambrian Mountains of mid Wales...

 and its estuary

Severn Estuary

The Severn Estuary is the estuary of the River Severn, the longest river in Great Britain. Its high tidal range means it has been at the centre of discussions in the UK regarding renewable energy.-Geography:...

. However, there is little direct evidence for dating the exploitation of iron ore from scowles.

The most likely origin of the word "scowle" is that it derives from a Brythonic word crowll meaning a cave or hollow, or the Welsh

Welsh language

Welsh is a member of the Brythonic branch of the Celtic languages spoken natively in Wales, by some along the Welsh border in England, and in Y Wladfa...

 word ysgil meaning a recess. Welsh was the main language in the local area before about the 9th century.

Characteristics

There are various types of scowles, ranging from deep irregular quarry-like features to amorphous shallow hollows. Shallow depressions could be either scowles which have been backfilled, or could represent subsidence of the ground surface above old mines or natural caves. Small pits with mounds of spoil associated with them probably represent different types of iron ore
extraction in the vicinity of the exposed cave system, or people prospecting for iron ore away from the main deposits. Small circular pits without associated mounds might represent
natural geological features.

Ecologically, scowles are now recognised as important wildlife habitats, being home to lower plants and ferns, bats and invertebrates. However, some are threatened by illegal dumping

Litter

Litter consists of waste products such as containers, papers, wrappers or faeces which have been disposed of without consent. Litter can also be used as a verb...

 and off-road vehicles.

Tourism and popular culture

One of the most accessible areas of scowles is at Puzzlewood

Puzzlewood

Puzzlewood is an ancient woodland site, near Coleford in the Forest of Dean, Gloucestershire, England. The site, covering 14 acres, shows evidence of open cast iron ore mining dating from the Roman period, and possibly earlier....

 near Coleford

Coleford, Gloucestershire

Coleford is a small market town in Gloucestershire, England in the west of the Forest of Dean with a population of 8,351 . It is situated some four miles east of the Welsh border, and is close to the Wye Valley, a popular walking and canoeing area...

, which is open as a tourist attraction. Over a mile of pathways were laid down in the early 19th century to provide access to the woods, and provide picturesque

Picturesque

Picturesque is an aesthetic ideal introduced into English cultural debate in 1782 by William Gilpin in Observations on the River Wye, and Several Parts of South Wales, etc. Relative Chiefly to Picturesque Beauty; made in the Summer of the Year 1770, a practical book which instructed England's...

 walks. Puzzlewood, and "Dwarf's Hill" at Lydney Park

Lydney Park

Lydney Park is a 17th century country estate surrounding Lydney House, located at Lydney in the Forest of Dean district in Gloucestershire, England. It is known for its gardens and Roman temple complex.-House and gardens:...

 which also contains scowles, are said to have been inspirations

J. R. R. Tolkien's influences

In his writings, in particular the fantasy novel The Lord of the Rings as well as the related novel The Hobbit and the posthumously published collection of stories The Silmarillion, J. R. R. Tolkien is cited as having had a number of influences...

 for J. R. R. Tolkien

J. R. R. Tolkien

John Ronald Reuel Tolkien, CBE was an English writer, poet, philologist, and university professor, best known as the author of the classic high fantasy works The Hobbit, The Lord of the Rings, and The Silmarillion.Tolkien was Rawlinson and Bosworth Professor of Anglo-Saxon at Pembroke College,...

's descriptions of Middle-earth

Middle-earth

Middle-earth is the fictional setting of the majority of author J. R. R. Tolkien's fantasy writings. The Hobbit and The Lord of the Rings take place entirely in Middle-earth, as does much of The Silmarillion and Unfinished Tales....

 in The Lord of the Rings

The Lord of the Rings

The Lord of the Rings is a high fantasy epic written by English philologist and University of Oxford professor J. R. R. Tolkien. The story began as a sequel to Tolkien's earlier, less complex children's fantasy novel The Hobbit , but eventually developed into a much larger work. It was written in...

. Tolkien carried out archaeological work in the area in the 1920s with Mortimer Wheeler

Mortimer Wheeler

Brigadier Sir Robert Eric Mortimer Wheeler CH, CIE, MC, FBA, FSA , was one of the best-known British archaeologists of the twentieth century.-Education and career:...

.