Archaeology andgeology continue to reveal the secrets ofprehistoric Scotland, uncovering a complex past before theRomans brought Scotland into the scope ofrecorded history. Successive human cultures tended to be spread across Europe or further afield, but focusing on this particular geographical area sheds light on the origin of the widespread remains and monuments in Scotland, and on the background to thehistory of Scotland.

The extent of open countryside untouched byintensive farming, together with past availability of stone rather than timber, has given Scotland a wealth of accessible sites where the ancient past can be seen.

Scotland is geologically alien to Europe, comprising a sliver of the ancient continent ofLaurentia (which later formed the bulk ofNorth America). During theCambrian period the crustal region which became Scotland formed part of the continental shelf of Laurentia, then still south of the equator. Laurentia was separated from the continent ofBaltica (which later becameScandinavia and theBaltic region) by the diminishingIapetus Ocean. The two ancient continents moved toward one another through the Cambrian andOrdovician periods, withtectonic folding during theSilurian pushing the first Scottish land above water. The final collision occurred during theDevonian period, with the Scottish segment of the Laurentian plate smashing intoAvalonia (which contained what is now most ofEngland andWales), a motile subcontinent which had previously joined with Baltica. This impact threw up a massive chain of mountains (at least as tall as the present-dayAlps) and saw the formation of the graniticWest Highland andGrampian mountain chains and (through theCarboniferous) a period of volcanic activity in central and eastern Scotland. During thePermian andTriassic periods, with theIapetus Ocean entirely closed, Scotland lay near the centre of thePangaean supercontinent. At the start of theTertiary, a constructive plate boundary (at which tectonic plates move apart) became active between Laurentia and Eurasia, pushing the two apart (and parting Scotland from Laurentia). This recession opened theAtlantic Ocean for the first time, and the consequentsubduction zone at the western plate margin led to a renewed period ofvolcanism, this time on Scotland's west coast, producing fresh mountains onSkye,Jura,Mull,Rùm, andArran.

This tectonic activity produced the basis of Scotland's topography: ancient mountains in the North and South of the country, partially eroded by 400 million years of water and ice with a wide fertile valley between them, and a newer, wilder western terrain. With Scotland now in the northern temperate zone, it was subjected to numerous glaciations in theNeogene andQuaternary periods, the ice sheets and their attendant glaciers carving the landscape into a typical postglacial one,overdeepening river valleys into the characteristic U-shape and leaving the upland areas covered with glacialcorries and dramatic pyramidal peaks. In lowland areas the ice deposited rich fields of fertile glacial till and eroded the softer material surrounding the extinct volcanoes (particularly the older Carboniferous ones), leaving manycrags.

During the lastinterglacial, around 130,000–70,000 BC, there were times when the climate in Europe was warmer than it is today, and after theNeanderthals came to prominence^{[clarification needed]} there was another mild spell around 40,000 BC. Neanderthal sites have been found in the south of England from this era, though no traces of early modern humans have been found. Repeated glaciations, which covered the entire land mass of modern Scotland, may have destroyed traces ofhuman habitation that existed before theMesolithic period.

Glaciers then scoured their way across most of Britain, and it was only after the ice retreated about 15,000 years ago that Scotland again became habitable.

As the climate improved,mesolithichunter-gatherers extended their range into Scotland. The earliest evidence to date is theflint artefacts found at Howburn Farm, nearElsrickle in 2005. This is the first and so far the only evidence ofUpper Paleolithic human habitation in Scotland, around 12,000 BC, which appears to fall between theYounger Dryas andLomond Stadial periods when cold conditions returned relatively briefly.^[1][2][3]

An early settlement atCramond, near what is todayEdinburgh, has been dated to around8500 BC. Pits and stakeholes suggest a hunter-gatherer encampment, andmicrolith stone tools made at the site predate finds of similar style in England. Although no bones or shells had survived in the acidic soils, numerous carbonised hazelnut shells indicate cooking in a similar way to finds at other Mesolithic period sites, including the slightly earlierStar Carr and theHowick house inNorthumberland, dated to7600 BC ("Britain's oldest house"), where post holes indicate a very substantial construction, interpreted as a permanent residence for hunting people. This suggests that hunter-gatherers could also have settled down in Scotland.

Other sites on the east coast and at lochs and rivers, and large numbers of rock shelters and shellmiddens around the west coast and islands, build up a picture of highly mobile people, often using sites seasonally and having boats for fishing and for transporting stone tools from sites where suitable materials were found. Finds of flint tools on Ben Lawers and at Glen Dee (a mountain pass through the Cairngorms) show that these people were capable of travelling well inland across the hills.

At a rock shelter and shell midden atSand, Applecross inWester Ross facingSkye, excavations have shown that around 7500 BC people had tools of bone, stone and antlers, were living off shellfish, fish, and deer using "pot boiler" stones as a cooking method, were making beads from seashells, and had ochre pigment and used shellfish which can produce purple dye.

Neolithic farming brought permanent settlements. AtBalbridie inAberdeenshire crop markings were investigated, and ditches and post holes found, revealing a massive timber-framed building dating to about 3600 BC. An almost identical building, with evidence of pottery, was excavated at Claish near Stirling.^[4] On the islet ofEilean Domhnuill, in Loch Olabhat onNorth Uist,Unstan ware pottery suggests a date of 3200–2800 BC for what may be the earliestcrannog.Neolithic habitation, burial, and ritual sites are particularly common and well preserved in theNorthern Isles andWestern Isles, where a lack of trees led to most structures being built of local stone.^[5]

The remainder of this section focuses mainly on theOrkney Islands, where there is a Neolithic landscape rich in sites amazingly preserved by prevalent use of the local stone which appears on the shore ready-split into convenient building slabs. There are many other examples across the country, many under the care ofHistoric Scotland.

At the stone house atKnap of Howar on theOrkney island ofPapa Westray (occupied from 3500 BC to 3100 BC) the walls stand to a low eaves height, and the stone furniture is intact. Evidence frommiddens shows that the inhabitants kept cattle, sheep and pigs, farmed barley and wheat and gathered shellfish, as well as fishing for species which must be caught from boats using lines. Finely made and decoratedUnstan ware pottery links the inhabitants tochambered cairn tombs nearby and to sites far afield, includingBalbrindi andEilean Domhnuill.

The houses atSkara Brae on theMainland of theOrkney Islands are very similar, but are grouped into a village linked by low passageways. This settlement was occupied from about 3000 BC to 2500 BC. Pottery found here is of thegrooved ware style which is found across Britain as far away asWessex.

About 6 miles (10 km) from Skara Brae,grooved ware pottery was found at theStanding Stones of Stenness (originally a circle) which lie centrally in a close group of three major monuments.Maeshowe, the finest example of thepassage grave type ofchambered cairn (radiocarbon dated to before 2700 BC) lies just to the east. TheRing of Brodgar circle of standing stones is across a bridge immediately to the north. This circle was one of the first to be analysed by ProfessorAlexander Thom to establish the likely use of standing stones as astronomical observatories. AnotherNeolithic village has been found nearby atBarnhouse Settlement, and the inference is that these farming people were the builders and users of these mysterious structures.

Like the standing stones atCallanish onLewis and other standing stones across Scotland, these monuments form part of the Europe-wideMegalithic culture which also producedStonehenge inWiltshire and the stone rows atCarnac inBrittany.

Further evidence can be found inKilmartin Glen with its Stone Circles, Standing Stones and Rock Art.

The widespread connections of these people are shown by offerings imported fromCumbria andWales and left on the sacred hilltop atCairnpapple Hill,West Lothian, as early as 3500 BC.

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  Ring of Brodgar, Orkney
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  Jade axehead, imported from theItalian Alps
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  The 'Westray Wife'
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  Cup and ring marks
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  The Towie carved stone ball
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  Carved stone balls
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  Stone mace and axes

The cairns andmegalithic monuments continued into theBronze Age, though there was a decline in both the building of large new structures and the total area under cultivation.^[6]

TheClava cairns and standing stones nearInverness show complex geometries and astronomical alignments, with smaller, perhaps individual, tombs instead of the communal Neolithic tombs.^[7]

Mummies dating from 1600 to 1300 BC have been discovered atCladh Hallan onSouth Uist.

Hill forts were introduced, such asEildon Hill near Melrose in theScottish Borders, which goes back to around 1000 BC and which accommodated several hundred houses on a fortified hilltop. Excavation atEdinburgh Castle found lateBronze Age material from about 850 BC.

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  All-over corded beaker,Bell Beaker culture
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  Gold lunula, Lanarkshire, 2300-2000 BC^[8]
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  Jet necklace, c. 2140-1900 BC^[9]
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  Bronze swords, c. 1000 BC
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  Bronze Agehorse harness
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  Bronze spearheads
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  Bronze shield
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  ReconstructedCrannog atLoch Tay
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  Eildon Hill
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  Cairnpapple Hill burial and ritual site
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  Gold armlet and neck torc, c. 1000 BC
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  Adabrock Hoard,Isle of Lewis, c. 1000 BC
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  Bronze razor, c. 900 BC
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  Wooden wheel remains,Blair Drummond, 1260-810 BC

From around 700 BC and extending intoRoman times, theIron Age was an age of forts and defended farmsteads, which support the image of quarrelsome tribes and petty kingdoms recorded by the Romans. Evidence that at times occupants neglected the defences might suggest that symbolic power was as significant as warfare.^[10]

Brythonic (or "Pritennic")Celtic culture and language spread into southern Scotland at some time after the 8th century BC, possibly through cultural contact rather than mass invasion, and systems of kingdoms developed.

Larger fortified settlements expanded, such as theVotadini stronghold ofTraprain Law,East Lothian, which was the size of a town. Huge numbers of smallduns,hill forts andring forts were built on any suitablecrag or hillock. The spectacularbrochs were built, most impressively the nearly completeMousa Broch,Shetland. ManySouterrain underground passageways were constructed, though their purpose is obscure. Island settlements linked with land by a causeway, thecrannogs, became common; it is thought that their function was defensive.

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  Illustration ofCaledonian kingCalgacus
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  Horse helmet, 300-200 BC.^[12]
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  Gold torcs,Stirling hoard, 300-100 BC
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  Stirling hoard gold torc, 300-100 BC
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  Scabbard, c. 1st century AD
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  Deskford carnyx & reconstruction.^[13]
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  Carnyx reconstruction
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  Horse harness, Middlebie Hoard, 1st-2nd century AD.^[14]
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  Bronze bracelets, c. 100 AD
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  Reconstruction of anIron Age chariot.^[15]

• Timeline of prehistoric Scotland
• Prehistoric Orkney
• Prehistoric Britain
• List of prehistoric structures in Great Britain
• Early history of Ireland
• Genetic history of the British Isles

• Scotland Since Prehistory: Natural Change and Human Impact, byChristopher Smout, 1993, Scottish Cultural Press,ISBN 1-898218-03-X
• Mesolithic Scotland and Its Neighbours, byAlan Saville, 2004,Society of Antiquaries of Scotland,ISBN 0-903903-28-8
• Scotland: From Prehistory to the Present, by Fiona Watson, 2003,ISBN 0-7524-2591-9
• The Early Prehistory of Scotland, byTony Pollard and Alex Morrison, 1996,ISBN 0-585-10420-4
• The Later Prehistory of the Western Isles of Scotland, by Ian Armit, 1992,ISBN 0-86054-731-0
• Prehistoric Scotland, by Ann MacSween and Mick Sharp, 1989,ISBN 0-7134-6173-X
• Guide to Prehistoric Scotland, by Richard Feachem, 1977, Simon & Schuster
• Prehistoric Scotland, by Richard Feachem and Urho Kekkonen, 1963
• A Guide to Prehistoric Scotland, by Richard Feachem, 1963, Batsford
• Prehistoric Scotland, byVere Gordon Childe, 1940, G Bell and Sons
• The Prehistory of Scotland, by Vere Gordon Childe, 1935, K Paul, Trench, Trubner & co
• Prehistoric Scotland and Its Place in European Civilization, by Robert Munro, 1899, W Blackwood and sons
• Scottish Archaeological Research Framework (ScARF)
• Toghill, Peter,The Geology of Britain, an introduction, Airlife (2000),ISBN 1-84037-404-7
• The Other Orkney Book, Gordon Thomson, Northabout Publishing 1980,ISBN 0-907200-00-1
• Scotland Before History, Stuart Piggott, Edinburgh University Press 1982,ISBN 0-7524-1400-3
• Scotland's Hidden History, Ian Armit, Tempus (in association with Historic Scotland) 1998,ISBN 0-85224-348-0

• An online exhibition on prehistoric sites in Scotland from Historic Environment Scotland
• Overview of the periods of Scotland's prehistory from Dig It!, part of the Society of Antiquaries of Scotland