Slate quarry trail

The route starts at Jeffrey's Pit in Trebarwith Valley and climbs through the woods and fields to Jenkins Quarry. It then follows a cattle-droving track into Delabole, passing the quarrymens' cottages along Pengelly, until it reaches Delabole Quarry. The route skirts around the edge of the quarry and then heads back down Bowithick Hill. It passes through the Bowithick Quarry slate tips to the Prince of Wales Quarry before completing the circle, returning along Sanding Road to Jeffrey's Pit.

Vital statistics

  • OS Explorer: 109 (scan QR code on right to order from Amazon)
  • Distance: 5.1 miles/8.2 km
  • Grade: Moderate
  • Start from: Jeffrey's Pit
  • Parking: Jeffrey's Pit. Turn down the road to Trebarwith Strand from the B3263 at the bottom of Trewarmett Hill. The car park is about 100 metres down on your left. Satnav: PL340EU
  • Recommended footwear: waterproof boots

Maps for this walk

(dark blue corner = laminated version)

Highlights

  • Pretty wooded valley at Jeffrey's Pit
  • Delabole slate quarry - once the biggest man-made pit in the world
  • Panoramic views over Trewarmett Downs, Trebarwith Valley and Port Isaac Bay
  • Wildflowers covering the slate tips in spring and early summer
  • Restored engine house at the Prince of Wales quarry
  • Variety of wildlife such as buzzards, kestrels, badgers and stoats

Directions

  1. Walk up the left-hand side of the stream from the parking area, past the picnic bench, to reach the woods.

    Jeffrey's Pit, located at the top of the road to Trebarwith Strand, is an old slate quarry and was still working in the early 20th century, closing in 1928. Alf Burrell, who lived in Trewarmett and died in the 1970s, started work there as a boy, making tea using the water from the stream. The cutting sheds were on the opposite side of the road (now a house), and as you walk down the road to the beach, the slate tips are walled up on your right. The slate tips cover the stream, which re-emerges below them to continue its path down the valley.

  2. Follow the path into the woods, which follows the stream up the valley. Continue on the path up a short incline past an old flight of concrete steps to where path climbs in a long incline up a steep bank.

    Upstream of Jeffrey's Pit, at the top of Trebarwith Valley, the public footpath runs for a 15-20 minute walk alongside the stream through ancient woodland. Few people go up here, so it's a peaceful spot and a good place to see wildlife. In early spring, you're likely to see frogs breeding in the stream. In April and May, the woodland floor is carpeted in bluebells contrasted by brilliant celandine, primroses and delicate wood sorrel flowers - an indicator that this has been under woodland for a long time.

  3. When you reach the steep bank, climb up carefully as this can be slippery in wet weather. Follow the path from the top of the bank, past a walled quarry pit on your left, until the path crosses through the stream.

    Some estimates suggest the UK has up to half of the world's total bluebell population; nowhere else in the world do they grow in such abundance. However, the poor bluebell faces a number of threats including climate change and hybridisation from garden plants. In the past, there has also been large-scale unsustainable removal of bulbs for sale although it is now a criminal offence to remove the bulbs of wild bluebells.

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  4. Cross the stream to the opposite bank then turn left behind the wooden fence and immediately keep right at the fork, following the path uphill to a kissing gate into a field.
  5. Go through the kissing gate and climb the steep field, following the left hedge to reach a pair of gates beside a concrete wall at the top of the field.

    In August, blackberries start to ripen on brambles. Blackberries are closely related to raspberries and technically neither is a berry but an aggregate of many individual tiny fruits, each containing a tiny stone like a miniature cherry. Blackberries are high in vitamin C, K and antioxidants. The seeds, despite being a bit crunchy, contain omega-3 and -6 fatty acids and further enhance blackberries' "superfood" status.

    According to folklore, you should not pick blackberries after Michealmas Day (11th October) as this is when the devil claims them. The basis for this is thought to be the potentially toxic moulds which can develop on the blackberries in the cooler, wetter weather.

  6. Go through the rightmost of the gates ahead, into the farmyard, and bear left to the gate next to the barn.

    Trenowth Farm is from the Cornish word noweth and means "new farm". The term is somewhat relative as it dates back to mediaeval times, being recorded as Trenewyth in 1327.

  7. Go through the gate and follow the lane away from the farm until you reach a sharp bend to the right with a metal farm gate on the left.
  8. Bear left off the lane and follow the grass to the gate into a field. Go through the gate and follow the right hedge to another gate, half-way along the hedge.
  9. Go through the gate and then cross the field to a gateway to the right of the telegraph pole in the middle of the field.
  10. Go through the gate and head straight across the field to a stone stile in the opposite corner.

    The slate tips on the right are from Trebarwith Road Rustic Quarry.

    Trebarwith Road Rustic Quarry is located on the road from Delabole to Trebarwith village. The quarry was originally known as "Jenkins Quarry" and reopened in the 1990s under the new name. As well as rustic slate, Blue Elvan is also quarried here.

  11. Cross the stile onto a lane and cross the pair of stiles opposite. Once in the field, head towards the church on the horizon, to a stile in the middle of the left hedge.

    Elvan is very hard volcanic rock formed where magma intruded into other rocks to form a (vertical) dyke or (horizontal) sill that cooled fairly quickly, resulting in fairly small crystals. Chemically it is very similar to granite, but in the case of granite, slower cooling resulted in large crystals. Elvans can be seen in many of the churches across Cornwall where it is often used for intricate parts of buildings, such as doorways, so they can be finely carved.

    The term "greenstone" is used by quarrymen to describe igneous rocks that, unlike granite, are rich in iron and magnesium and these give it a blue-green colour. When greenstone is formed as a sill or dyke it is sometimes called "blue elvan". This is also quite common in Cornwall and has been quarried for a long time: in the Neolithic period, stone axes made from blue elvan were exported from Cornwall to various parts of Britain.

  12. Cross the stile to emerge onto a track. Turn right and follow the track to a stile.
  13. Cross a stile and follow the grassy track to a gate.

    The group of wind turbines to the left is Delabole Wind Farm.

    The Delabole windfarm was the first commercial windfarm in the UK, built in 1991 partly due to local opposition to a proposed nuclear power station which would have been somewhat suboptimal for the tourism on which Cornwall depends. In the 20 years since the Delabole windfarm was first built, the technology improved significantly. In 2011, the 10 original turbines were replaced with just 4 new models which are significantly more powerful and efficient. The cabling for the turbines is all underground and there are no access roads which allows the land beneath the turbines to be farmed.

  14. Cross the stile next to the gate onto a track by a farm. Follow the track past the houses on the left until you reach a metal gate on the left, opposite a footpath on the right, signposted to Treligga.
  15. Turn left through the gate and follow the path alongside the builders yard to another gate.
  16. Go through the gate and follow the lane down to the main road.
  17. Turn left towards the Bettle and Chisel, following the road until you reach a junction to the right (Pengelly).

    The Bettle & Chisel is a public house on the main road in Delabole nearly opposite the lane to Pengelly. The pub takes its name from two of the tools historically used by slate quarrymen - bettle is a local dialect word for a lump (club) hammer. "The Bettle", as it's known locally, was, and still is, a favourite hangout of the quarry workers. The bar attests to just how much of a pub can be made from slate!

  18. Turn right down Pengelly and follow this to the end, until you reach Delabole Quarry.

    Delabole Quarry is over a mile in circumferance and was once the deepest man-made pit in the world. It is England's oldest slate quarry; the first written records of a slate order date from 1314 and slate almost certainly from Delabole has been found in prehistoric settlements on Bodmin Moor. Delabole slate is noted for its uniform colour, durability and imperviousness to rain, making it ideal for roofing. There is a visitor centre (open Mon to Fri 8am - 4:30pm) with some interesting historical photos including the Duke of Windsor (then Prince of Wales), plummeting down the tram line into the quarry! Guided tours of the quarry are available at 2pm daily, Mon-Fri from the start of May to the end of August.

  19. Walk through the car park to the left of the visitor's centre (ahead), and follow the track to the quarry viewing platform.
  20. Facing the quarry, turn right onto the path around the quarry; follow it to the junction with a track.

    The layers of slate in the quarry were eloquently described in 1758: "The strata in the following order: the green sod, one foot; a yellow brown clay, two feet; then the rock, dipping inwards into the hill towards the south-west, and preserving that inclination from top to bottom: at first the rock is in a lax shattery state, with short and frequent fissures, the lamina of unequal thickness, and not horizontal: thus the rock continues to the depth of ten or twelve fathom, all which is good for nothing, and entirely to be rid off; then comes in a firmer brown stone, which becomes still browner in the air; this is fit for slating houses, and the largest size for flat pavement never sweating as the cliff slate, which is exposed to the sea air. This is called the top-stone, and continues for ten fathom deep, the stone improving somewhat as you sink, but not at the best till you come to twenty-four fathom deep from the grass; then rises what they call the bottom-stone, of a grey blue colour, and such a close texture, that on the touch it will sound clear, like a piece of metal. The principal horizontal fissures, which divide the strata, run from ten to fifteen feet asunder; they are no more than chinks or joints, and contain no heterogeneous fossil. The stone of this quarry weighs to water as 2-(62/121) are to 1, is not subject to rot or decay, to imbibe water, or split with falling, as the bottom-stone of Tintagel, and other quarries; but for its lightness, and enduring weather, is generally preferred to any slate in Great-Britain."

  21. Cross over the track and bear left onto the waymarked path along the fence. Follow this to a kissing gate and stile leading into a field.

    The working of the quarry is described in 1758 as follows: "The whole quarry is about three hundred yards long and one hundred wide: the deepest part from the grass is judged to be forty fathoms. The masses are first raised rough from the rock by wedges driven by sledges of iron, and contain from five to ten, twelve or fourteen feet, superficial square of stone: as soon as this mass is freed by one man, another stone-cutter, with a strong wide chisel and mallet, is ready to cleave it to its proper thin-ness, which is usually about the eighth of an inch; the shivers irregular from two feet long, and one foot wide, downwards, to one foot square and sometimes (though seldom) dividing into such large flakes as to make tables and tomb-stones. In this quarry several parties of men work on separate stages or floors, some twelve fathom from the grass, some twenty, others forty fathom deep, according to the portion of ground belonging to each party; the small shattery stone, not fit for covering houses, serves to shore up the rubbish, to divide the different allotments, and shape the narrow paths up and down the quarry; all the slate is carried with no small danger from the plot where it rises, on men's backs, which are guarded from the weight by a kind of leathern apron, or rather cushion; the carrier disposes his charge of stones in rows side by side, till the area allotted to his partners is full, and then horses are ready to take them off, and carry them by tale to the person that buys them."

  22. Go through the gate and follow along the fence on the left to reach another stile and kissing gate.

    The working in 1882 had changed with the advent of the steam engine: "The scene is enlivened by a throng of men busily engaged in various noisy employments, while waggons and horses are everywhere in rapid motion, and steam-engines are lifting with a harsh sound their ponderous arms, and raising loaded trucks from the depths of the pit, or masses of slate of several tons' weight, which are seen slowly ascending guide-chains to stages which overhang the quarry. The quarry is about 260 ft. in depth. Upon the edge of the quarry is the Papete Head, a projecting platform, from which a number of guide-chains are stretched like the shrouds of a ship to the base of the pit. The slate is first loosened by small charges of gunpowder ; it is then torn up by wedges and crowbars, and placed in trucks, which, being attached to a wheel which traverses a guide-chain, are drawn up by the steam-engine some feet above the Papete Head, Movable stages, called hatches or tables, are then run out under the trucks, which, being lowered upon a framework on wheels, are drawn away by horses to the different workshops, where the slate is split into various sizes, according to the purpose it is intended to serve. The water is pumped from the quarry by water-wheels into an adit, and the slate is shipped at the little harbours of Port Gaverne, Port Isaac, and Boscastle, the former being the principal port in the summer, the latter in the winter, as affording the best shelter to the vessels. About 1000 men are employed in these works, who raise on an average 120 tons of slate per day." ("Papete" is thought to be a local abbreviation of "Parapet").

  23. Go through the gate and follow the left fence to join a stony path at a waymark. Follow this along the fence to reach a kissing gate on the corner of the fence.

    The huge pieces of slate winched from the quarry by steam engines were known as "steamers". Occasionally, a chunk would fall off one, back into the quarry, or a chain would snap and whip into the edge of the quarry, causing a rockfall. Landslips also occurred occasionally, due to faults in the rock above the face being quarried, or material on the edges of the pit collapsing. There were a number of injuries and fatalities but also some miraculous escapes. One quarrymen was saved by his pasty, which a cheeky raven grabbed and he gave chase, narrowly avoiding a landslip where he had been standing. Another quarrymen, ascending a ladder, was hit in the backside by a flying piece of slate and found himself sat, unhurt, on the grass at the side of the quarry pit!

  24. Go through the gate and turn left, following the path along the fence to a gate leading to the houses on the right.

    Even in Victorian times, slate was blasted with black powder (aka gunpowder), rather than high explosives such as dynamite. This is because high explosives combust with a supersonic shockwave known as a detonation wave, travelling at a speed of more than a mile per second. This causes very high pressure and resulting high temperature in the explosive, setting off neighbouring parts. This would shatter the brittle slate into tiny pieces, rather than breaking off large chunks.

    As fuse technology improved, holes were drilled at regular intervals along a quarry face, filled with black powder. These pockets were all blasted simultaneously using a linked fuse (electrically triggered in the latter years of quarrying), to break off a very large chunk of slate. You can sometimes see the blasting holes in waste pieces of slate on the slate tips.

  25. Continue ahead along the fence to pass the gate and reach a flight of steps with a metal handrail on the right.
  26. Climb the steps and turn left onto the lane. Follow the main lane (ignoring junctions to the left) until it ends in a T-junction with the main road.
  27. Cross the main road and turn right onto the pavement. Follow this past some houses until you see a track on your left marked with a public footpath sign.

    The road from Port Gaverne which joins the Delabole road was quarried out in the early 1800s by the Delabole Slate company and known as "The Great Slate Road". Around 100 ships a year came to Port Gaverne to collect slate, each capable of carrying 50-80 tonnes. It would take thirty wagons, pulled by over a hundred horses, to load a sixty ton ship. The slates were loaded by women, who then packed them in straw to protect them on the voyage. The incoming ships also brought coal from Wales and limestone, for the local limekiln, which was used to whitewash the cottages.

  28. Turn left down the track marked with a footpath sign, and follow it to a stile at the end.
  29. Cross over the stile on your right and bear left across the field towards the opposite left corner to reach a stile about 30 metres to the right of the field corner.

    If you are crossing fields in which there are cows:

    • Do not show any threatening behaviour towards calves (approaching them closely, making loud noises or walking between a calf and its mother) as you may provoke the mother to defend her young. Generally the best plan is to walk along the hedges.
    • If cows approach you, do not run away as this will encourage them to chase you. Stand your ground and stretch out your arms to increase your size.
    • Avoid taking dogs into fields with cows, particularly with calves. If you can't avoid it: if cows charge, release the dog from its lead as the dog will outrun the cows and the cows will generally chase the dog rather than you.
  30. Cross the stile into the next field and cross the field diagonally to stile in the opposite corner between the two gateways.
  31. Turn right and follow the track to where it ends at a gate onto a lane.
  32. Cross the stile on the left of the gate then turn left onto the lane and continue a short distance to a junction.
  33. Turn right and walk carefully along this lane (there are some blind corners) down a hairpin bend to a junction at the bottom of Bowithick Hill.

    The acidic soil in the Tintagel area was fertilised with lime-rich beach sand from nearby Trebarwith Strand, where the golden sand is largely composed of sea shells which are mostly calcium carbonate (chemically identical to chalk and limestone).

    The sand at Trebarwith Strand was also put to another use: to avoid several tonnes of slate in a wagon going down the steep road through Trebarwith Valley resulting in horse paté, the slate wagons would be loaded with sand from Trebarwith Strand and this would be scattered on the road on the way back up, to act as a braking system.

    The trade in sand and slate quarrying led to road improvements in the early 19th century and for one reason, or the other, or possibly both, the Trebarwith Strand to Condolden road is known as "Sanding Road".

  34. Turn right at the junction and walk a short distance along the road until you reach the entrance to the Prince of Wales quarry on your left (a double gate with a metal bar above).
  35. Turn left into the quarry and bear right, through a gate, to a junction in the path.
  36. Where the path forks, take the left path (more or less straight ahead) which climbs through the slate tips then levels out. Follow this until, just before the path ends, you reach a a few slate steps on your right leading up onto a wall.

    The path ends in a platform which overlooks a waterfall, tumbling into the quarry pit. This is the stream that runs across Trewarmett Downs. When the quarry was being worked, the engine house pumped the water out of the pit, to prevent it flooding, and also powered slate-hauling equipment to lift the slate out of the pit.

    The Prince of Wales quarry is in Trebarwith Valley, overlooking Trewarmett. The quarry opened in 1871 but was only worked for just over 20 years, closing 1890s; the slate quarried here was blue slate from the Upper Devonian Penpethy Beds. A circular path now leads through the old slate tips, past the quarry pit (now a lake with a small waterfall) and up to the engine house which has good views of the valley and coastline.

  37. Take the steps and follow the path up the side of the slate tip to the top, where there is a good view over the quarry pit.

    Cornwall's iconic engine houses were built to house huge beam engines - a type of steam engine with a pivoting beam. This configuration was particularly suited to powering pumps to stop the quarry pits and mines from flooding as water trickled into them from above. Inside the engine house, steam from a boiler would push up a piston, causing the beam to tilt downwards, pushing the pump down into the shaft. The steam would then be shut off and cold water would be used to condense the steam within the piston back into water, creating a partial vacuum. Atmospheric pressure then pushed the piston back down into the vacuum, raising the beam and lifting water out of the shaft. The valves to apply the steam and cold water were mechanically automated, maintaining a steady rocking motion of the giant beam.

  38. At the top of the steps, turn left along the wall and follow the path down to the engine house door.

    The engine house in Trewarmett is the only one preserved in North Cornwall. It was built in 1870 and the beam engine, installed in 1871, was used to drive a wire ropeway to haul slate, as well as pumping water out the quarry pit (which is now a lake). You can safely wander around inside (there are grilles covering the pit which once contained the beam engine).

  39. Facing out from the engine house doorway, take the path to the left and descend a series of steps. When you reach the bottom, turn left to reach the gate through which you entered.
  40. Go through the gate and make your way down to the main road.
  41. Turn right onto the main road and walk past the quarries, towards Trewarmett, until you reach a junction signposted to Trebarwith Strand at the bottom of the hill.
  42. Turn left down the road to Trebarwith Strand, and left again into Jeffrey's Pit, to complete the circular walk.

Help us with this walk

You can help us to keep this walk as accurate as it possibly can be for others by spotting and feeding back any changes affecting the directions. We'd be very grateful if could you look out for the following:

  • Any stiles, gates or waymark posts referenced in the directions which are no longer there
  • Any stiles referenced in the directions that have been replaced with gates, or vice-versa
  • If you have a large dog, let us know if you find problems with the stiles on this walk (e.g. require the dog to be lifted over). A rough idea of how many problematic stiles there are is also useful.

Take a photo and email contact@iwalkcornwall.co.uk, or message either IWalkCornwall on facebook or @iwalkc on twitter. If you have any tips for other walkers please let us know, or if you want to tell us that you enjoyed the walk, we'd love to hear that too.

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