Crannog

A crannog    (crannóg ; crannag) is typically a partially or entirely artificial island, usually built in lakes, rivers and estuarine waters of Scotland and Ireland. Unlike the prehistoric pile dwellings around the Alps which were built on the shores and were inundated only later on, crannogs were built in the water, thus forming artificial islands.

Crannogs were used as dwellings over five millennia, from the European Neolithic Period to as late as the 17th/early 18th century, although in Scotland there is currently no convincing evidence in the archaeological record of Early and Middle Bronze Age or Norse Period use. The earliest radiocarbon determinations obtained from key sites such as Oakbank in Loch Tay and Redcastle, Beauly Firth approach the Late Bronze Age - Early Iron Age transition at their widest interpretation at 2 standard deviations or a 95.4% confidence level: they fall after around 800 BC and so could be considered Late Bronze Age by only the narrowest of margins. Crannogs have been variously interpreted as free-standing wooden structures, as at Loch Tay, although more commonly they exist as brush, stone or timber mounds which can be revetted with timber piles. However, in areas such as the Western Isles of Scotland, timber was unavailable from the Neolithic era onwards. As a result, completely stone crannogs supporting drystone architecture are common here. Today, crannogs typically appear as small, circular islets, often 10 to 30 m in diameter, covered in dense vegetation due to their inaccessibility to grazing livestock.

Etymology and uncertain meanings
The Irish word crannóg derives from Old Irish crannóc, which referred to a wooden structure or vessel, stemming from crann, which means "tree", plus a diminutive ending—literally "young tree". The modern sense of the term first appears sometime around the 12th century; its popularity spread in the medieval period along with the terms isle, ylle, inis, eilean, oileán. There is some confusion on what the term crannog originally referred to, the structure atop the island or the island itself. The additional meanings of 'crannog' can be variously related as "structure/piece of wood; wooden pin; crow's nest; pulpit; driver's box on a coach and vessel/box/chest" for crannóg. The Scottish Gaelic form is crannag and has the additional meanings of "pulpit" and "churn". Thus there is no real consensus on what the term crannog actually implies, although the modern adoption in the English language broadly refers to a partially or completely artificial islet which saw use from the prehistoric to the Post-Medieval period in Ireland and Scotland.

Location
Crannogs are widespread in Ireland with an estimated 1,200 examples, while Scotland has 347 sites officially listed as such. The actual number in Scotland varies considerably depending on definition—between about 350 to 500, due to the use of the term "island dun" for well over one hundred Hebridean examples—a distinction that has created a divide between mainland Scottish crannog and Hebridean islet settlement studies. Previously unknown crannogs in Scotland and Ireland are still being found as underwater surveys continue to investigate loch beds for completely submerged examples. The largest concentrations of crannogs in Ireland are found in the Drumlin Belt of the Midlands, North and Northwest. In Scotland, crannogs favour a western or 'Atlantic distribution', with high concentrations in Argyll and Dumfries and Galloway. In reality, the Western Isles contain the highest density of lake-settlement in Scotland, yet they are recognised under varying terms besides "crannog". One lone Welsh example at Llangorse Lake exists, likely a product of Irish influence across the Irish Sea.

Reconstructed Irish crannógs are located in Craggaunowen, Ireland; the Irish National Heritage Park, in Wexford, Ireland; and in Scotland at the "Scottish Crannog Centre" at Loch Tay, Perthshire. This centre offers guided tours and hands-on activities, including wool-spinning, wood-turning and making fire, holds events to celebrate wild cooking and crafts, and hosts yearly Midsummer, Lughnasadh and Samhain festivals.

Types and problems with definition
Crannogs took on many different forms and methods of construction based on what was available in the immediate landscape. The classic image of a prehistoric crannog stems from both post-medieval illustrations and highly influential excavations such as Milton Loch in Scotland by C.M. Piggot after World War II. The Milton Loch interpretation is of a small islet surrounded or defined at its edges by timber piles and a gangway, topped by a typical Iron Age roundhouse. The choice of a small islet as a home may seem odd today, yet waterways were the main channels for both communication and travel until the 19th century in much of Ireland and especially Highland Scotland. Crannogs are traditionally interpreted as simple prehistorical farmsteads. They are also interpreted as boltholes in times of danger, as status symbols with limited access and as inherited locations of power which imply a sense of legitimacy and ancestry towards ownership of the surrounding landscape.

A strict definition of a crannog, which has long been debated, requires the use of timber. Sites in the Western Isles do not satisfy this criterion, although their inhabitants shared the common habit of living on water. If not classed as "true" crannogs, small occupied islets (often at least partially artificial in nature) may be referred to as "island duns", although rather confusingly, 22 islet-based sites are classified as "proper" crannogs due to the different interpretations of the inspectors or excavators who drew up field reports Canmore search for crannog in the Western Isles Hebridean island dwellings or crannogs were commonly built on both natural and artificial islets, usually reached by a stone causeway. The visible structural remains are traditionally interpreted as duns, or in more recent terminology as "Atlantic roundhouses". This terminology has recently become popular when describing the entire range of robust, drystone structures which exist in later prehistoric Atlantic Scotland.

The majority of crannog excavations were poorly conducted (by modern standards) in the late 19th and early 20th centuries by early antiquarians, or were indeed purely accidental finds as lochs were drained during the improvements to increase usable farmland or pasture. In some early digs, labourers merely hauled away tons of materials with little regard to anything that was not of immediate economic value. Conversely, the vast majority of early attempts at proper excavation failed to accurately measure or record stratigraphy, thereby failing to provide a secure context for artefact finds. Thus only extremely limited interpretations are possible. Preservation and conservation techniques for waterlogged materials such as logboats or structural material were all but non-existent, and a number of extremely important finds perished as a result: in some instances dried out for firewood. From about 1900 to the late 1940s there was very little crannog excavation in Scotland, while Ireland did witness some important and highly influential contributions. In contrast, relatively few crannogs have been excavated since the Second World War, although this number has steadily grown, especially since the early 1980s, and may soon surpass pre-war totals. The overwhelming majority of crannogs show multiple phases of occupation and re-use, often extending over centuries. Thus the re-occupiers may have viewed crannogs as a legacy that remained alive in local tradition and memory. Crannog reoccupation is important and significant, especially in the many instances of crannogs built near natural islets that were often completely unused. This long chronology of use has been verified both by radiocarbon dating and more precisely by dendrochronology. Interpretations of crannog function are not static through time; instead they appear to change in both the archaeological and historic records. Rather than largely simple domestic residences in prehistory, medieval crannogs were increasingly seen as strongholds of the upper class or regional 'political players' such as Gaelic chieftains like the O'Boylans and McMahons in County Monaghan and the Kingdom of Airgíalla until the 17th century. In Scotland, their medieval and post-medieval use is also documented into the early 18th century. Whether this increase in 'status' is real, or just a by-product of increasingly complex material assemblages remains to be convincingly validated.

History
The earliest construction of a crannog is the completely artificial Neolithic islet of Eilean Domhnuill, Loch Olabhat on North Uist in Scotland. Eilean Domhnuill has produced radiocarbon dates ranging from 3650 to 2500 BC while Irish crannogs appear from middle Bronze Age layers at Ballinderry (1200–600 BC). Prior to the Bronze Age, the existence of artificial island settlement in Ireland is not as clear. While lakeside settlements are evident in Ireland from 4500 BC, these settlements are not crannogs as they were not intended to be islands. Despite having a tremendous chronology, their use was not at all consistent or unchanging. Crannog construction and occupation was at its peak in Scotland from about 800 BC to AD 200. Not surprisingly, crannogs have useful defensive properties, although there appears to be more significance to prehistoric use than simple defense as very few weapons or evidence for destruction appear in excavations of prehistoric crannogs. In Ireland, crannogs were at their zenith during the Early Historic period when they were the homes and retreats of kings, lords, prosperous farmers and occasionally socially marginalised groups such as monastic hermits or metalsmiths who could work in isolation. However, despite earlier concepts of a strict Early Historic evolution, Irish excavations are increasingly uncovering examples which date from the "missing" Iron Age in Ireland.

Construction
The construction techniques for a crannog (prehistoric or otherwise) are as varied as the multitude of finished forms witnessed in the archaeological record. Island settlement in Scotland and Ireland is manifest through the entire range of possibilities ranging from entirely natural, small islets to completely artificial islets, therefore definitions will invariably remain contentious. For 'crannogs' in the strict sense, typically this effort began on a shallow reef or rise in the lochbed. When timber was available, many were surrounded by a circle of wooden piles with axe-sharpened bases that were driven into the bottom, forming a circular enclosure that helped to retain the main mound and prevent erosion. The piles could also be joined together by mortise and tenon, or large holes cut to carefully accept specially shaped timbers designed to interlock together and provide structural rigidity. On other examples, interior surfaces were built up with any mixture of clay, peat, stone, timber or brush- whatever was available. In some instances, more than one structure was built on crannogs. Other types of crannogs saw the occupants add large stones to the waterline of small natural islets, extending and enlarging them over successive phases of renewal. Larger crannogs could be occupied by extended families or communal groups, and access was either by logboats or coracles while evidence for timber or stone causeways exists on a large number of crannogs. The causeways themselves may have been slightly submerged; this has been interpreted as a device to make access difficult yet this can also simply be a by-product of loch level fluctuations over the ensuing centuries or indeed millennia. Organic remains are often found in excellent condition on these water-logged sites. The bones of cattle, deer, and swine have been found in excavated crannogs while remains of wooden utensils and even dairy products can remain completely preserved for several millennia.