Thirlmere and Dunmail Raise: The Drowned Villages and the Buried King

The main road through the heart of the Lake District – the A591 between Grasmere and Keswick, which every visitor travels sooner or later – carries two of the district's darkest and best stories within a few miles of each other. Beneath the long, quiet waters of Thirlmere lie the remains of a drowned valley: farms, an inn, a bridge and the twin settlements of Armboth and Wythburn, submerged when Victorian Manchester dammed the lake for drinking water in one of Britain's first great environmental battles. And at the road's summit, on the grass between the two carriageways, stands a large ancient cairn under which – so legend insists – lies Dunmail, last king of Cumberland, slain in battle a thousand years ago and waiting, some say, to rise again. Our tours pass this way on nearly every circuit, and no stretch of road repays storytelling better. Here is what lies beneath the water and under the stones.

Thirlmere: the lake that Manchester made

Thirlmere today reads as a wild, dark, conifer-flanked ribbon of water beneath the huge western wall of the Helvellyn range – and almost everything about that scene is Victorian engineering. The original valley held a smaller, narrower lake (in places so pinched it was crossed by a bridge) with a scatter of farms and two little communities along its shores. In the 1870s, booming industrial Manchester, desperate for clean water, fixed on the valley as its reservoir: an Act of Parliament was fought through against passionate opposition, a great dam was built at the northern end, and by the mid-1890s the raised waters had swallowed the valley floor – Armboth and Wythburn's scattered homes among the losses, though Wythburn's little chapel survives above the waterline on the eastern shore, a lonely white survivor our guests often ask about. The water then set off on one of the engineering marvels of the age: an aqueduct roughly ninety-six miles long, flowing to Manchester entirely by gravity – no pumps, just a gradient of inches per mile – and still performing its quiet miracle today; a glass of water in Manchester begins as Lakeland rain on Helvellyn.

The battle that helped invent conservation

The flooding of Thirlmere matters far beyond the valley, because the fight against it effectively founded modern landscape conservation. The Thirlmere Defence Association – drawing on Wordsworth's old vision of the district as "a sort of national property" and marshalled by figures including John Ruskin's circle and the young Canon Hardwicke Rawnsley of Keswick – lost the battle but built the movement: Rawnsley carried the lessons directly into co-founding the National Trust in 1895, and the arguments first rehearsed over Thirlmere (beauty as a public good; the burden of proof on the despoiler) run through every landscape controversy since, down to the National Park's creation in 1951 and the district's UNESCO World Heritage inscription. The valley itself has softened with time – the once-controversial conifer plantations are being diversified, the shore paths and viewpoints (Launchy Gill's cascades, the western shore road's framed prospects of Helvellyn) reward a pause, and red squirrels haunt the woods – details from the National Park at lakedistrict.gov.uk. But the drowned walls are still down there, and in drought summers, when the water drops, old lanes and boundaries ghost back into the light – the Lake District's own Atlantis, surfacing on schedule.

Dunmail Raise: the cairn between the carriageways

South of Thirlmere the road climbs gently to its summit at Dunmail Raise, the lowest and flattest of the district's famous passes – and squarely on the top, marooned on the central reservation where the road divides, sits a great heap of stones that traffic streams past at sixty miles an hour. The legend attached to it is magnificent: here, around the year 945, Dunmail – last king of Cumberland – fell in battle against the English king Edmund, and his warriors raised the cairn over him where he lay; the fuller versions add that his surviving men carried his golden crown up the fellside and cast it into Grisedale Tarn beneath Helvellyn, where it waits – and that the king himself only sleeps, until the day he reclaims it. Historians note drily that the real Dunmail (Dyfnwal, a historical tenth-century king of Strathclyde and Cumbria) probably died decades later and elsewhere; the cairn itself has never given up its secrets. The legend, needless to say, has comfortably outlived the objections – and cresting the Raise with the story fresh, Grisedale's fells rising to the east, is one of the small reliable pleasures of the road. It marks a genuine frontier too: for centuries this pass was effectively the border country between Scots-claimed Cumbria and England, and it still divides the district's waters – rain falling south of the cairn reaches the sea via Windermere, rain to the north via Derwentwater.

The wall of Helvellyn

One more feature dignifies this stretch: the entire eastern side of the road is the western rampart of the Helvellyn range – England's third-highest mountain and its most climbed big summit, whose famous ridge routes (Striding Edge chief among them) attack from the far, Ullswater side while this flank presents a single vast wall of fellside, seamed with gills and old pony paths. The classic western ascent, from Wythburn's little church by the reservoir shore, has been tramped since Victorian times – Wordsworth climbed Helvellyn into his seventies – and on clear days the summit people are visible from the road as pinpricks on the skyline, two and a half thousand feet above your seat. Few main roads anywhere run so long in the shadow of so much mountain.

Reading the road

The A591 across Dunmail Raise and along Thirlmere is, on the surface, simply the quick way from Grasmere to Keswick – and underneath, a layered text of drowned farms, Victorian ambition, a founding conservation battle, a sleeping king and a watershed of the realm. That transformation – tarmac into narrative – is precisely the job of a good guide. On our small-group scenic tours from Windermere and Ambleside – maximum seven guests – this stretch links the day's southern and northern theatres, and the stories of Manchester's long straw and Dunmail's crown are told where they happened, water and cairn in view. Every landscape hides its history somewhere. The Lake District, with characteristic flair, hides one chapter under a lake and parks another in the middle of the road.

This article is part of our scenic Lake District guides collection – twenty in-depth guides researched and written by our local team. Browse the full library on our Travel Guide Library.