The bedrock of Lewis and Harris is Lewisian gneiss, laid down three billion years ago. It is among the oldest exposed rock anywhere on Earth - hard, impermeable, scoured smooth by ice. Where it lies flat as on Lewis, the gneiss has been overlaid by peat bog and forms a low boggy plateau. Where it crumples upward as on Harris, it makes the gnarly heights that give the southern island its character. Either way, the rock supports almost no agriculture - rough grazing for sheep is about all it allows, plus garden crops of kale and later potatoes. There is no mineral wealth here, no industrial future ever proposed that worked. The inhabitants scratched a living from sheep, kelp, fish and weaving. Clisham, north of Tarbert, rises to 799 metres - the highest hill in the entire Western Isles, and the only Corbett in the archipelago.

Roads did not exist on Harris until modern times. People got about by sea, and the sea brought the Vikings. From the seventh and eighth centuries onwards, the Norse settled and traded across the Outer Hebrides, and their place-names survive almost everywhere despite later Gaelicisation. Norse rule weakened in the thirteenth century, and after the Norwegian defeat at the Battle of Largs in 1263, the Hebrides were formally ceded to Scotland - though Norway kept Orkney and Shetland. After Largs the Gaelic clan chiefs governed under a feudal system, with service rather than cash as the unit of obligation. That system died at Culloden in 1746, and what replaced it was money - and landlords who lived far away, made their money far away, and saw the Hebrides as a balance sheet. The Highland Clearances followed in the nineteenth century. Whole villages were cleared. The emptiness of Harris today is what remained when the people left.

In the early twentieth century the whole of Lewis and Harris was bought by William Hesketh Lever - Lord Leverhulme - the soap tycoon. He arrived with grand industrial plans and considerable money. On Lewis there was a great falling-out: returning First World War servicemen had been promised land, and many of them were taking it as small crofts. Leverhulme called them squatters, took them to court, lost his political battle with the Scottish Office, and gave up on Lewis. On Harris there was less friction. He concentrated his investment at the village of Obbe, renamed it Leverburgh in 1920, and built a herring fishery there. Then he caught pneumonia in Africa and died in 1925. His Lever Brothers executors wound up the project; it had cost £500,000 and produced very little. The village kept the name. The pier he built still works.

Harris Tweed survived where Leverhulme's herring did not. The handwoven woollen cloth had been a domestic textile across the Outer Hebrides for centuries, dyed with local lichens and plants, woven on treadle looms in crofters' houses. In Victorian society it became fashionable as sturdy practical wear - shooting jackets, country suits, the uniform of a certain kind of British gentleman. Mainland mills inevitably started producing imitations, and there was a real risk of the genuine cottage industry being swamped. The Orb trademark was granted in 1909 to protect the authentic product. Further legal protection followed in 1993 with the Harris Tweed Act, defining Harris Tweed as cloth handwoven by islanders at their homes in the Outer Hebrides, finished in the Outer Hebrides, and made from pure virgin wool dyed and spun in the Outer Hebrides. Walk into any weaver's house on Harris today and you can hear the rhythm of the treadle loom. The trademark is one of very few protected designations in British textile history.

Harris is divided by the deep notches of West and East Loch Tarbert; Tarbert village sits on the narrow isthmus between them and is the main ferry port. The west coast has the famous beaches - Luskentyre and Seilibost regularly rated among the best in the world, pale sand against turquoise water with the Harris hills behind. The east coast is rocky and broken, threaded by the Golden Road - the narrow switchback lane between Tarbert and Rodel, named for the expense of building it across boulder-strewn moorland. South of Leverburgh stands the medieval church at Rodel, dedicated to St Clement and dating to the early sixteenth century, with carved tombs of the MacLeod chiefs inside. The Postman's Path above Rhenigidale is a hiking route across abandoned country, passing villages emptied long ago. Take a boat from Leverburgh to St Kilda if the weather permits - it usually does not. Take another to the Shiant Islands for puffins and seals.