Elterwater Quarry

Overview

A green slate quarry at the foot of the Langdale valley in the Lake District, worked since at least the mid-19th century and still producing today, prized for the distinctive pale green colouring — with contrasting markings — of its volcanic stone.

History

Quarrying at Elterwater is documented from the mid-19th century, working the same Borrowdale Volcanic Group slate exploited across the central Lake District. The quarry has operated, with periods of dormancy, into the present day, and is now one of several Cumbrian quarries run by Burlington Stone.

Elterwater is one of the sources of what the trade calls Westmorland Green, or Lakeland Green — a group name for the green slates of the Borrowdale Volcanic Group rather than a single quarry's product, alongside Broughton Moor, Brandy Crag, Bursting Stone, Honister and Kirkstone. The names matter commercially because the stone from each source differs slightly in colour and figure while the geology is shared. Ownership followed the consolidation that shaped the whole Cumbrian industry: the quarry was bought by the Old Delabole Slate Company, the Cornish firm, and passed in 1976 to Burlington, whose own business had grown from the darker Kirkby-in-Furness stone that gives Burlington slate its name. Elterwater is one of the handful of Cumbrian workings still active, with Kirkby, Broughton Moor and Kirkstone, out of an industry the Cumbria Industrial History Society describes as a fraction of its size at the turn of the 20th century.

Geology

Elterwater's slate is a metamorphosed volcanic ash of the Ordovician-age Borrowdale Volcanic Group, around 450-500 million years old, giving it a harder, tougher character than sedimentary slates and its characteristic pale green colour.

Workings

Slate has been worked both by open quarrying on the fellside and by tunnelling into the hillside, leaving a network of underground chambers alongside the open workings.

Closure

Unknown.

What remains

Still an active Burlington Stone quarry, with planning permission to work slate at Elterwater until 2042, and open enough for a right of way to run through part of the workings. Part of the site has separately been the subject of a long planning fight over an adventure-tourism attraction in the disused underground and surface workings. The Lake District National Park Authority's development control committee refused an application in September 2023 on traffic grounds; a revised application was submitted in January 2024 and granted in May 2024 (application 7/2023/5767). Friends of the Lake District brought a judicial review, heard in Manchester on 30 April 2025, arguing that the Authority had misjudged the traffic in the Langdales, the tranquillity of the valley and its duty to conserve the park's natural beauty. On 14 October 2025 the Authority reported that Mr Justice Mould had dismissed every ground of the claim and upheld the permission, agreeing with the Authority's application of the Sandford Principle.

Working faces, benches and slate spoil runs on the fellside above Elterwater and Chapel Stile, with walls built to hold back the waste; gated tunnel mouths into the underground chambers; and dressing and stocking yards where blocks and finished slate stand waiting to go out.

Related mines

• Banks Slate Quarry, Chapel Stile — Neighbouring Langdale green-slate workings; Elterwater is the survivor still at work.
• Kirkby Slate Quarries — Both are Burlington quarries: Elterwater passed to Burlington in 1976, and Kirkby-in-Furness is the company's original working and the source of the darker Burlington slate against which Elterwater's Westmorland Green is sold.
• Lords Quarry — Lord's is one of the quarries grouped as the Elterwater Quarries.

What's uncertain

Points where sources disagree or the record could not be settled; both accounts are kept. All open questions in the archive.

• Part of the quarry's underground workings has been proposed for redevelopment as a heritage tourist attraction, a plan that has met public objection locally. (uncertain) ¹

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• Elterwater's slate is a metamorphosed volcanic ash of the Ordovician-age Borrowdale Volcanic Group, around 450-500 million years old. ¹
• Part of the quarry's underground workings has been proposed for redevelopment as a heritage tourist attraction, a plan that has met public objection locally. (uncertain) ¹
• The quarry was bought by the Old Delabole Slate Company and passed to Burlington in 1976; it trades its stone as Westmorland Green, one of several named sources of that slate. ^2,3
• Planning permission for an adventure-tourism attraction at the quarry (application 7/2023/5767) was refused in September 2023, granted in May 2024, and upheld by the High Court on all grounds in a ruling reported by the National Park Authority on 14 October 2025 after a judicial review brought by Friends of the Lake District. ⁴
• The quarry holds permission to work slate until 2042 and remains one of the few Cumbrian slate quarries still active, with Kirkby, Broughton Moor and Kirkstone. ²

Photographs & further reading

Sources

1. (secondary) Elterwater — Wikipedia
2. (secondary) Slate — the Cumbrian slate industry, its geology, working and decline — Cumbria Industrial History Society
3. (secondary) Great British Stone: Cumbrian slate — Stone Specialist
4. (primary) Elterwater Quarry planning decision upheld — Lake District National Park Authority
5. (secondary) Our Quarries — Burlington Stone

Record created: 25 August 2026 · Last researched: 11 September 2026