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.

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.

What remains

Still an active Burlington Stone quarry as of the mid-2020s; part of the site's underground workings has separately been proposed for redevelopment as a heritage tourist attraction, a plan that has drawn public objection locally.

Abandoned workings can be dangerous — unstable ground, uncapped shafts, flooding and bad air are common even where a site looks safe from the surface. This entry describes history and general location only; it is not an access guide.

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. (high) 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. (medium) ¹

Photographs & further reading

This page doesn't try to reproduce everything — these are the best original sources found for this mine.

Images

Sources

1. (secondary) Elterwater — Wikipedia
2. (primary) Mine plan: ELTERWATER QUARRY — BGS mine plans catalogue (Cumbrian Amenity Trust Historical Mining Society collection)
3. (secondary) Our Quarries — Burlington Stone

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