A denehole (alternatively dene hole or dene-hole) is an underground structure consisting of a number of small chalk caves entered by a vertical shaft. The name is given to certain caves or excavations in

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

, which have been popularly supposed to have been created by the

Danes Danes ( da, danskere, ) are a North Germanic ethnic group and nationality native to Denmark and a modern nation identified with the country of Denmark. This connection may be ancestral, legal, historical, or cultural. Danes generally regard t ...

or some other of the early northern invaders of the country. The common spelling Dane hole is adduced as evidence of this, and individual names, such as Vortigern's Caves at

Margate Margate is a seaside town on the north coast of Kent in south-east England. The town is estimated to be 1.5 miles long, north-east of Canterbury and includes Cliftonville, Garlinge, Palm Bay and Westbrook. The town has been a significan ...

, and

Canute Cnut (; ang, Cnut cyning; non, Knútr inn ríki ; or , no, Knut den mektige, sv, Knut den Store. died 12 November 1035), also known as Cnut the Great and Canute, was King of England from 1016, King of Denmark from 1018, and King of Norway ...

's Gold Mine near

Bexley Bexley is an area of south-eastern Greater London, England and part of the London Borough of Bexley. It is sometimes known as Bexley Village or Old Bexley to differentiate the area from the wider borough. It is located east-southeast of Ch ...

, naturally follow the same theory. The word, however, is probably derived from the

Anglo Saxon The Anglo-Saxons were a cultural group who inhabited England in the Early Middle Ages. They traced their origins to settlers who came to Britain from mainland Europe in the 5th century. However, the ethnogenesis of the Anglo-Saxons happened wi ...

''den'', a hole or valley. The lack of evidence found in them has led to long arguments as to their function.

Form

The general outline of the formation of these caves is invariably the same. The entrance is a vertical shaft some 3 feet (1 m) in diameter falling, on an average, to a depth of 60 feet (20 m). The depth is regulated by the depth of the

chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. C ...

layer from the surface, although chalk can be found within a few feet, or even inches, from the surface. A depth of from 45 to 80 feet or more, is a characteristic feature. Footholds were cut into the sides of the shaft to allow people to climb in and out. The shaft, when the chalk is reached, widens out into a domed chamber with a roof of chalk some 3 feet thick. The walls frequently contract somewhat as they near the floor. As a rule the main chamber is 16 to 18 feet in height, beneath each shaft. From this excessive height it has been inferred that the caves were not primarily intended for habitations or even hiding-places. In most cases, between two and four sub-chambers are present, excavated laterally from the floor level, the roof being supported by pillars of chalk left standing.

Distribution

There are many underground excavations in the south of England, also found to some extent in the

Midlands The Midlands (also referred to as Central England) are a part of England that broadly correspond to the Kingdom of Mercia of the Early Middle Ages, bordered by Wales, Northern England and Southern England. The Midlands were important in the In ...

and the north, but true deneholes are found chiefly in those parts of

Kent Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it faces ...

and

Essex Essex () is a Ceremonial counties of England, county in the East of England. One of the home counties, it borders Suffolk and Cambridgeshire to the north, the North Sea to the east, Hertfordshire to the west, Kent across the estuary of the Riv ...

along the lower banks of the

Thames The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...

. With one exception there are no recorded specimens farther east than those of the

Grays Thurrock Grays or Greys may refer to: Places * Grays Bay, Nunavut, Canada * Grays, Essex, a town in Essex, England ** Grays railway station ** Grays School * Grays, Kent, a hamlet in Kent, England * Rotherfield Greys or Greys, a village in Oxfordshire, ...

district, situated in Hangman's Wood, on the north, and one near Challock on the south side of the river south of Faversham. Isolated specimens have been discovered in various parts of Kent and Essex, but the most important groups have been found at Grays Thurrock, in the districts of

Woolwich Woolwich () is a district in southeast London, England, within the Royal Borough of Greenwich. The district's location on the River Thames led to its status as an important naval, military and industrial area; a role that was maintained thr ...

Abbey Wood Abbey Wood is an area in south east London, England, straddling the border between the Royal Borough of Greenwich and the London Borough of Bexley. It is located east of Charing Cross. Toponymy The area takes its name from Lesnes Abbey Woo ...

and Bexley, and at Gravesend. Those at Bexley and Grays Thurrock are the most valuable still existing. It is generally found that the tool work on the roof or ceiling is rougher than that on the walls, where an upright position could be maintained.

History

Pliny the Elder Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic ' ...

wrote about British chalk extraction in A.D. 70 and archaeological evidence shows that at least some of the deneholes were being exploited during prehistory. Casts taken of some of the pick-holes near the roof show that, in all probability, they were made by bone or horn picks. Numerous bone picks have been discovered in Essex and Kent. These pick-holes are amongst the most valuable data for the study of deneholes, and have assisted in fixing the date of their formation to pre-Roman times. However, very few artifacts which would provide dating evidence or assisted in determining the uses of these prehistoric excavations have been discovered in any of the known deneholes.

Chrétien de Troyes Chrétien de Troyes (Modern ; fro, Crestien de Troies ; 1160–1191) was a French poet and trouvère known for his writing on Arthurian subjects, and for first writing of Lancelot, Percival and the Holy Grail. Chrétien's works, including ...

has a passage on caves in Britain which may have reference to deneholes, and tradition of the 14th century treated the deneholes of Grays as the fabled gold mines of Cunobeline (or

Cymbeline ''Cymbeline'' , also known as ''The Tragedie of Cymbeline'' or ''Cymbeline, King of Britain'', is a play by William Shakespeare set in Ancient Britain () and based on legends that formed part of the Matter of Britain concerning the early Celti ...

) of the 1st century. In 1225 Henry III gave every man the right to sink a

marl Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. Marl makes up the lower part ...

pit on his own land. Spreading chalk on the fields was a common practice in the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...

. This appears to have continued into the 19th century. The need for chalk in agriculture supports the theory that the origin of deneholes was for chalk extraction. Vortigern's Caves at Margate are possibly deneholes which have been adapted later for other purposes; and excellent examples of various pick-holes may be seen on different parts of the walls. Local tradition in some cases suggests the use of these caves by

smuggler Smuggling is the illegal transportation of objects, substances, information or people, such as out of a house or buildings, into a prison, or across an international border, in violation of applicable laws or other regulations. There are various ...

s. Illicit traffic was common not only on the coast but in the Thames as far up the river as

Barking Creek Barking Creek joins the River Roding to the River Thames. It is fully tidal up to the Barking Barrage (a weir), which impounds a minimum water level through Barking. In the 1850s, the creek was home to England's largest fishing fleet and a Vic ...

. The theory is at least plausible that these ready-made hiding-places, which were difficult of approach and dangerous to descend, were used in this way.

Purpose

Information sign about the Dene Hole in Capstone Park - geograph

By the end of the nineteenth century, three purposes had been suggested for which deneholes may have been originally excavated: * as hiding-places or dwellings * storehouses for grain. * drawwells for the extraction of chalk for agricultural uses For several reasons it is unlikely that they were used as habitations, although they may have been used occasionally as hiding-places. Silos, or underground storehouses, are well known in the south of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

and

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to A ...

. It has been suggested that the grain was stored unthreshed and carefully protected from damp by straw. A curious smoothness of the roof of one of the chambers of the Gravesend twin-chamber denehole has been put forward as additional evidence in support of this theory. Since the 1950s the theory that they were ancient chalk mines has gained acceptance. This was formerly thought unlikely as it was reasoned that chalk could have been obtained outcropping close by. J.E.L. Caiger worked in Kent excavating, surveying and researching deneholes and concluded that they were excavated in prehistoric, Roman, medieval and even post-medieval times in order to produce a supply of unpolluted chalk to spread on fields for the purposes of marling. By excavating a narrow shaft, the miners used up as little of the productive agricultural land as possible. He suggested various other practical issues which supported his ideas including that open cast chalk extraction would require moving the material further than necessary and that shallower chalk deposits have much of their minor mineral content leached out by groundwater. Another theory that has been advanced is that the excavations were made in order to get

flint Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and start ...

s for implements.

External links

Kent Underground Research Group page on deneholes

Collapse of Denehole in Grays

References