Tan-yr-Ogof 1-6 General area NGR: SH914779 Llandulas

Area plan showing caves 1 - 5

A group of 6 caves in an imposing limestone outcrop overlooking the Irish Sea.

The caves were named 'Tanyrogo' in "Records of Denbigh and its Lordship" (1860) by John Davies, and also in "The Netherworld of Mendip" (1907) by Baker & Balch. The name presumably derives from the nearest property indicated on early OS maps: 'Tan-yr-Ogof'. The name was later published as 'Tan-yr-Ogof Caves' in: Stride, A.H. & R.D. (1953) Britain Underground, by Dalesman Publishing.
The cave has also been described as 'Cefn-yr-Ogof,' although this actually refers to the highest point on the hillside above.

Four of the six caves (2, 3, 4, 5) appear to have been excavated, possibly in Victorian times, although s ignificant volumes of en-situ deposits still remain. No archaeology has been documented but i f excavated archaeologically at the time, it may be safe to assume that nothing was found.

Archaeologists briefly examined caves 2, 3, 4 & 5 in 2016 and came to the same conclusions as above . Their subsequent report does however add some interesting background information:
The most obvious Cave No 4 had been known for many years, but at the time of a visit in 1833 by Joshua Trimmer, he described other nearby caves as being filled with deposits. It appears that Caves 2, 3 & 5 were probably excavated at some time between 1838 and 1851 "at the behest of Lloyd Hesketh Bamford-Hesketh [1788-1861], who had Gwrych Castle built in the 1820s".
Cave 2: Approximately 150 cu.m. of deposits had been excavated.
Cave 3: The earliest graffitti dated 1851, lies below the pre-castle floor level of cave deposits.
Cave 5: Approximately 30-40 cu.m. of deposits had been excavated.
(Source: CPAT Report 1469, Jan. 2017).

Take the old road from Abergele towards Llandulas for 1.5 miles Then take the first road on the left. After a few hundred metres, find somewhere to park where a road called Clip Terfyn bears off to the right. Look for an old high stone wall running up into the hill near this road junction. The entrance to Cave 1 is found where the wall terminates against the outcrop. Footpaths can be found on the left (north) side of the wall leading to the other caves (see area plan below).

The caves are described and numbered walking north-east from Cave 1.

Ownership: Contact Gwrych Castle Preservation Trust, who in 2018 obtained ownership of Gwrych Castle.

Cave 1: SH9139977893 +/-15ft Length: 7m (to Cave 2)

Cave entrance measures 2.5m wide by 1.1m high. This quickly reduces in size to a crawl which enters Cave 2 at roof level.
The cave contains unexcavated deposits which extend outside the cave entrance (see first photo below).
Directly above a stone wall which runs up from the road called Clip Terfyn.


Cave No. 1, showing what appear to be marine deposits outside the entrance

Cave No 1 showing the crawl passage that connects with Cave 2 at roof level
Photo: Jerry Dobby

Cave 2: SH 9140277905 +/-22ft (May 2015) Length: 19m
An entrance of 3m wide by 5m high becomes a passage up to 10m high, blocked by clay deposits after 10m where a low passage on the right enters Cave 1.
At the top of the clay blockage is a crawl excavated by the writer and the late Tony Jarratt in the 1970s for 8 metres to a very small chamber blocked by further deposits (personal diary 1974).
No archaeological material was found during this work.
Close to roof level in the left-hand wall is a low crawl (Maypole Passage) running north-east and connecting to Cave 3 (See survey).
Unexcavated clay deposits block the end of the cave.

A few metres to the east of Cave 1 and 6m below it.

Cave No 2

Cave No 2 showing unexcavated deposits at the current end of the cave
Photo: Jerry Dobby

Cave 3: SH9142177910 +/- 16ft Length: 37m (Excluding Maypole Passage)
Entrance measures 3.1m wide by 3.8m high, leading to a 5m high winding passage with a smaller 7m passage on the right at the end.
Part way into the cave are two tubes high in the passage wall (maypoling required) six metres above floor level. The tube in the south wall connects to Cave 2.
Unexcavated clay deposits block the end of the cave.
Seventeen paces north of Cave 2

Cave No 3

Cave No 3

Cave 4: SH9150377964 +/-18ft Length: 67m
"The Ogo" (after Baker & Balch 1907)

A 8m x 8m diameter entrance immediately splits into two passages. The left ends after 10m. The main right-hand passage passes beneath a rift in the roof leading up to surface, within which an awkward climb leads to a 6m passage. Some 35 metres from the entrance the main passage becomes more silted at a point where a small chamber can be seen on the left. The main route closes down after a further 7m.

Unexcavated clay deposits block the end of the cave.

The largest of the entrances, facing north, lies a short walk further east around the outcrop (s ee Area Map above). It lies about 20m above the level of Cave No 3. It used to be clearly visible from the A55 expressway but trees now obscure the entrance.


Cave No 4 showing left and right passages. Note the 1 metre ranging pole for scale

Cave No 4 showing unexcavated deposits at end of passage, although nothing was noted that might suggest archaeological potential

Cave 4

Cave 5: SH9154477916 +/-20ft Length: 12m

Entrance measures 2.1m wide by 4m high. A straight rift passage with an aven in the roof about 6m high.

The end of the passage terminates at a vertical wall of calcited till (clay and boulders), suggesting the point at which early excavation was halted.

From Cave 4, see Area Map above .


Cave 5 in 2015

Cave 5 showing unexcavated deposits (50cm ranging pole)

Cave 5 in 2015

Cave 6: Length: 6m

A crawl becoming too tight.

This small cave was examined by John Blore in the 1960s.
NB The writer has been unable to locate this cave. It may require climbing gear to access from above as suggested by John Blore. If any reader knows its whereabouts, will they please let this website know.

Continue up path from Cave 5 via steps in cliff to the field above. The entrance lies almost directly above Cave 4 and is best reached by climbing down from above.


Ted's Cave SJ2110863165 Length: 3m Gwernymynydd

A passage with a circular cross-section just over a metre in diameter and found in the wall of a disused quarry. Although the cave is of little speleological interest, the passage ahead is blocked with deposits which may or may not hold archaeological potential.
If digging to extend the length of passage, please examine any disturbed deposits carefully.
First documented around 1980 by caver Ted Carr of Wavertree, Liverpool, the discoverer of Ogof Colomendy.

Take the Ruthin road out of Mold. At the top of the Gwernymynydd hill where it levels out, take the first turn right along a small lane. Park somewhere along here, then continue walking for about 500 metres to where the track bends to the left. Shortly after this, veer off the track to the left heading for a style in the fence beyond. Cross the style and follow a vague path keeping to the left of an old limekiln. The cave is in the furthest quarried overhanging rock face.

Looking into the slightly obscured cave entrance

Cave entrance

Deposits blocking continuing passage


Trevor Flood Resurgence Cave SJ24874224 Length 25m Llangollen

A short squeeze entrance leads to several clean-washed, but low crawl passages which all become too low.
The main passage descends gradually into the hill, following the dip of the limestone bedding.

In severe flood this cave resurges impressively. The entrance partially collapsed in the 1970s and may need a few slabs removing to gain entry. A few hundred metres to the east is the permanent, but unpromising small resurgence of Ty Canol which rises out of boggy ground at SJ25174222. Further east is the main rising for Ruabon Mountain, Oerog Spring. This has been built over by the water authority and is not accessible (although no limestone outcrops here and water is likely to rise to surface through alluvial gravels).

All three risings drain Ruabon Mountain (south of World's End), a catchment area three miles in length in which very few caves are known. The areas presumed main cave system may only form at depth as a result of percolation.

Look for a small dry stream valley running down to the main road. The entrance is at the head of this valley beneath a track which leads into a small old quarry nearby.


Trevor Hall Cave SJ2549142140 +/-17ft Length 25m Llangollen

Two entrances open into a chamber 4m wide and of stooping height. A passage 1m x 1.5m runs into the hillside for 10 metres to where it reduces in size to a crawl before becoming blocked after another 4 metres. At the furthest accessible point, a speleothem boss or column can be seen ahead, beyond which only badgers have explored. It appears an easy dig to extend the passage simply by lowering the clay floor a little.

The cave has been excavated at some time in the past, possibly by Victorian bone hunters, as evidenced by the remnants of a speleothem floor which can be seen on the walls a metre and a half above present-day floor level. If archaeologically excavated in the past, it seems likely that nothing archaeological was found, as no reports of the work appear to exist. Significant clay deposits remain however.

Many animal bones lie within the clay floor or rest upon it, but the floor deposits have been heavily disturbed and include modern-day detritus. The bones also appear to be of recent origin.

First examined by cavers from Shropshire Mining Club in 1962.

Permission: Trevor Hall

South-west of Trevor Hall is a small triangular-shaped wood which can be clearly seen from the road. The cave lies at the base of a rock outcrop within this wood.

Park on the verge by a farm gate at SJ2555141910 (just room for a car without blocking access). Take the nearby public footpath leading from the road, past a private house crossing two stiles, then bearing off to the right (following the ascending path and skirting the woods). Just before a derelict house in the woods, take another stile into the woods. Follow the rough path for about 30 metres, then head up directly towards the cliffs above. The cave should be close by.

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West entrance

East entrance (a vertical drop of 1.5m to cave floor level)

View upwards from East entrance

Passage and East entrance viewed from chamber


The point at which the passage reduces to a 4m long crawl to a speleothem boss

Remains of speleothem floor in wall

A sample of many animal remains


Trevor Rocks Cave SJ2406142962 +/-11ft Length: 5m Llangollen

A crawl-sized tube immediately beside the Panorama Road.
Appears to hold little promise beyond the Coke cans, bottles and boulders blocking the end.

Take the high road from Garth towards World's End. Just over a mile from Garth the road bends sharply to the left, then the right. The entrance is next to the road just after the right-hand bend.

Ty Mawr Reservoir Sink SJ05946302 Length 12m Denbigh
(Large House Reservoir Cave)

Ty Mawr reservoir has an overflow to the north which runs into a pool about 50m from the reservoir at a small rock outcrop. A hole appeared in the base of the pool in 1985 revealing a small passage. A group of cavers from Denbigh excavated this and entered a descending crawl which narrowed, turned sharp right and became too tight at the lowest point. May be worthy of a full-scale dig but the roof was reported to be in need of some support. In 1999 the cave was completely silted but may flush itself clear from time to time (see also Ffynnon Ddyfnog; the resurgence, and Ogof Rhewl; another, more promising sink linking to the same cave system).

The site is now difficult to reach, hence find the landowner and seek permission to visit.

Sketch only


Ty Newydd Caves 1-3 SJ0855572272 +/-15ft Tremeirchion Archaeological (rhino tooth in Cave 3)

Entry updated April 7th 2019 ( the writer did not fully explore the passages due to lack of caving gear).

The close proximity of the three caves suggests they may once have been part of the same cave system. They do not however, appear to be connected.

The cave contains plenty of haematite-stained clays requiring suitable clothing.

Cave 1 Length: 18m
(the largest entrance) : Just a metre or two inside the entrance is a 4m vertical rift in the floor. At the bottom of this rift, a roomy passage can be seen running off horizontally (see photo below). The 1960 description below states that this lower passage develops into a high rift passage 18m long. This terminates where the rift is 9m high and props can be seen in the roof.

Cave 2 Length: 4m
(Upper entrance directly above Cave 1): Simply a 4m passage ending at a blockage.

Cave 3 Length: 18m
(6m west of Cave 1): An entrance almost 3m high x 1m wide bears right and upwards into a chamber about 5m x 3m. The passage bears to the east at this chamber and ascends, according to Quote 2, for 15m.
NB This cave is unstable with large loose blocks in the roof and walls.

Access: The caves lie in a small quarry accessed through the garden of a private residential property. Permission should be sought before entering.

1960 description.....

From 'Caves of North Wales', 1960 by Davies & Ellis of Shepton Mallet Caving Club.......

Cave 1: Length: 18m

"The largest entrance, and the cave is used as a household rubbish tip. A ten feet drop, which requires a 20 foot rope, leads to sixty foot of high rift passage in a rectangular plan. At the far end of the cave the rift is at least thirty feet high and props were seen across the walls" (installed by the Victorian excavators or miners?).

Cave 2: (see note below) Length: 5m

"Is five feet vertically above Cave 1 but after 15 feet the passage is blocked by a wall of 'deads'" (evidence of mining).

Cave 3: Length : 15m

"Is twenty feet west of Cave 1. Ten feet from the entrance a thirty foot high aven leads to the top of the cliff. To the left the passage slopes steadily upwards for fifty feet".

"The caves are situated in the back garden of Ty-Newydd-y-Graig Cottage on the south side of the first lane running east from the south of Tremeirchion. The caves are in very red, sandy rock".

Additional 1949 details.....

From 'The Prehistoric & Roman Remains of Flintshire', 1949, by Ellis Davies…….

“Position: The entrance to these caves is hidden from the valley by a wall of rock, the space between this and the caves having been quarried away about 1850. The caves which are now practically inaccessible owing to growth of jungle, are in a dangerous condition as the rock is falling in".

"Exploration: ……… Owing to the proximity of Ty Newydd Cottage it was found impossible to approach the cave from the exposed front, so a cutting and tunnel through the solid rock had to be made from the hillside above. This work occupied the whole winter of 1896-97. The actual exploration was begun in March, 1897".

This description bears no relation to what was visible on the surface in 2019. Presumably the 'cutting and (mined) tunnel' simply provided excavators access to the lower passage of Cave 1, but has since been filled in.

Ellis Davies also states that seven excavations took place in the eastern cave (Cave 1?), and although a depth of 8ft was reached, no rock floor was found. No bones or implements were found. In the western cave (Cave 3), excavations were carried out at intervals along the cave, but again, no rock floor was found. The only find was a fragment of tooth identified as lower molar of Rhinoceros, found almost 47ft from the cave entrance.

Main and Upper entrances to the left. West entrance behind the caver.

Main and Upper entrances

Looking vertically down from the Main entrance into the lower passage
(Note the tripod leg at bottom of picture for scale)

View from the main entrance
(Photo taken with a fisheye lense, so it looks larger than it actually is)

Upper entrance

West entrance

Chamber inside west entrance

Looking up into the chamber of west entrance


White Horse Cave SJ18826502 Length 9m Alyn Gorge
A slightly descending 1m diameter tube blocked with sandy deposits. Excavated in the 1980s when the cave was extended by a metre or so. The sandy deposits contained nothing of archaeological interest.

About 200 metres south of the Cilcain-Pantymwyn bridge in an outcrop next to the river. From the car park by the road bridge follow the river upstream on the east bank. Continue as far as possible next to the river then skirt the outcrop for a few metres. The entrance is 3m above river level.


White Quarry Caves SJ16687592 Pantasaph

Updated August 15th 2016

White Quarry and Brown Quarry Extract from the 25":1 mile OS sheet

Google Earth plan of White Quarry

A small abandoned quarry just east of Pantasaph contains a number of small caves.
The quarry was one of several whose correct name is Grange Quarries. However the caves were first described in 1963 as White Quarry Caves. This name is used here as it helps differentiate it from another nearby quarry also containing caves: Brown Quarry (see Brown Quarry Caves on page 2).

Although not worked for many years, it was re-activated for a short time in the 1980s in the hope of extending its expiring planning consent. At that time earth-moving machinery changed the quarry considerably, blocking some caves and revealing others previously unknown. Therefore some of the caves listed here should not be compared or confused with those mentioned in:
Stride, A.H. & R.D. (1953) Britain Underground or Jenkins & Mason-Williams (1963 & 1967) Caves of Wales & the Marches, or elsewhere.

The writer visited the caves again in 2016 and found that three of the caves which were accessible before the 1980s disturbance, could not be found as their entrances had been obscured by filling , bringing the total of filled caves here to four. The Google Earth image above shows these as yellow circles. A short cave not previously mentioned on this site was noted in 2016 and is marked above as Cave C.

Lost Cave A

This is perhaps the largest cave to have been lost. Marked 'A' on the plan above, it was entered by the writer and the late Tony Jarratt in 1974. The entrance was excavated to reveal a vertical drop of about 15 feet, followed by a steep descent into a sloping-floored chamber about 9m long x 3m wide x 2.5m high. One wonders if this could perhaps have been the lost Barnewell Cave or Grange Farm Cave, mentioned in British Caving in 1953, although there is no evidence to support this.

"By digging through rubbish, we revealed a drop of 15ft to a steeply sloping passage terminating in a roomy chamber" (Source: writers diary 20/5/1974).

The visit is also mentioned in the on-line diaries of the late Tony Jarratt: "A rubbish-choked hole was dug to reveal a hole dropping into about 80ft of large natural (?) rift blocked by mud and some 30ft deep at the end" (Source: http://www.mcra.org.uk/logbooks/files/JRatVol2.pdf ). There is now no trace of the cave as its entrance appears to have been covered by several tons of earth.

Lost Cave B
A previously unrecorded tube was noticed in the quarry floor in 1987 after the quarry had been re-activated and again closed.
Marked as 'B' on the plan above, it was a tube about 0.8m diameter running 3m to a single jammed boulder, where the way ahead continued beyond. There is now no trace of the cave.

A quarter of a mile east of Pantasaph Priory, take the signed public footpath north for 200m. Turn left where the path turns left and right, and the quarry entrance is on your right after about 30 metres.

Cave 1: SJ1674975966 +/-15ft Length 2m

Entrance is just below the top of the cliff face. It may need a rope dropping down from above to climb up to the entrance. Not entered in 2016, but previously described as an uninspiring 2m tube.

Entrance in centre of photos near top of cliff face

Cave 2: SJ1673175886 +/-16ft Length: 3m

The entrance comprises a passage ahead becoming blocked after no more than 3m, and a narrow vertical rift partially blocked by a boulder at the top. The rift can be seen to descent to a depth of about 9m from the entrance, but it would need the entrance and boulder clearing away to see if the rift is wide enough to descend. Possibly the most promising of the White Quarry caves.

Cave 2 in side of 'ramp'

Open rift descends 9m

Cave 3 (Lost) : Length: 5m

A crawl leads to a low passage but the entrance is nearly blocked by boulders.

No trace in 2016: Appears to have been deliberately blocked by tipping.

Cave 4 (Lost): Depth: 4m

A narrow rift pot to a small chamber with no way on.

No trace in 2016: Appears to have been deliberately blocked by tipping.

Cave 5: SJ1667975982 +/-10ft Length: 2m

Uninspiring. 2m to silt and boulders.

Cave 5

Cave 6: SJ1666575985 +/-9ft Length: 1m

A short tube blocked by deposits after no more than 2m.

Cave 6

Cave 6

Cave 7: SJ1662475976 +/-15ft Length: 20m

Half way up the cliff face is a roomy entrance 2m wide by 3m high. The passage soon reduces in size becoming block by undisturbed deposits after 6m.

Cave 7

Cave 7

Cr awl at end of Cave 7

Cave 8: SJ1654475956 +/-12ft Length: 8m

A 3m vertical pot with its entrance at the top. This connects via a crawl at floor level to Cave 9.

View of Caves 8 and 9 from quarry entrance

Cave 8 (leading to Cave 9 below)

Cave 9: SJ1654475956 +/-12ft Length: 4m

A passage 1m in diameter is blocked after 3m. A crawl at floor level in the right hand wall leads after a metre or so to the foot of the 3m high tube which is Cave 8.

Cave 9 (below) and Cave 8 (above)

View from Cave 9

Cave C SJ1669175913 +/-9ft

A previously unrecorded cave in the south side of the ramp leading up out of the quarry.

An attempt has been made to seal the cave with chippings, but quick work with a trowel will provide access to a short crawl that appears to run for a few metres.

Cave C entrance lies in centre of photo

A few inches remains open a b ove the chippings


World's End Cave Length 100m+ SJ234477 World's End

A crouching-sized entrance lowers after a few metres to a low wet crawl. This can be pushed by experienced enthusiasts for 36m passing a 3m long low airspace duck and a 1.2m waterfall to a sump. This marks the ultimate limit of ‘dry’ exploration. The sump has been dived and is described as "a comfortable bedding plane 3m wide". Then 11m into the sump , an air-bell is reached , after which the sump becomes lower and wider. 30m into the sump the passage splits. To the right soon becomes too tight, but to the left is a low squeeze beyond which it gets very narrow. At a depth of 3m (53m into the sump), is a constriction and a silt bank, beyond which lies 30m of larger passage which rises above water level. A duck then leads to a 3m high rift and the limit of diving exploration" (Source: Welsh Sump Index, Cave Diving Group 1986).

Several short mine levels can also be found in the same area.

The possibility of other sealed caves nearby was mentioned in 1961: “On approximately the same bedding plane from which flows the World’s End stream, other low cave entrances can be seen in the cliffs on the southern side of the gorge. These all require digging out if they go anywhere at all being fairly well choked with gravel and earth. It was possible to see along one for about ten feet”. Source: “A General Reference to the Caving Areas of North Wales” 1961, Derbyshire Caving Club, Bulletin No.1.

Take the footpath from the ford at World's End upstream. The entrance is to the left of the path and a small stream can be seen flowing within. Several short mine levels also exist nearby.