12.08.15
Mynydd Llangynidr (SO 123 151) and Blaen Onneu (SO 147 159)
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| Blaen Onneu (SO 147 159) |
Mynydd Llangynidr and
Blaen Onneu are situated between two mountainous roads, the one to the east is
the B4560 and goes from Llangynidr in the north to Garnlydan in the south,
whilst the road to the west heads toward the Trefil Qarries and ends in a rough
track. The land between these two roads
where the hills are situated is unenclosed and gives a great sense of openness
with extended landscapes and tranquillity predominating. The land is also rather wild and if not for the
path between the hills it would be a rough traverse from one summit to the other.
We parked toward the top
of the Trefil road where there was still a semblance of tarmac, this road is
marked in yellow on current Ordnance Survey maps which indicates that it is
public, but unbeknownst to us the road is closed between the hours of 5.00pm –
6.30am when a barrier is brought down over it and locked. Unfortunately when we ended our walk we were
locked in, but more of that later.
Our first objective was
the critical bwlch of Mynydd Llangynidr which is listed as a 500m Twmpau as
well as a Hump with c 102m of drop. As
the summit of this hill is crowned by a large ancient cairn there is a
possibility that its 557m summit spot height is taken to the top of the cairn
and not to the natural ground at its base.
If this was so the hill may lose an all-important 2-3 metres from its
map height when accurately surveyed.
The lay of land at the
bwlch was not overly difficult to judge and soon the Trimble was placed on my
rucksack and gathering data with a 0.43m offset measured to take off after the
data were processed.
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| Gathering data at the critical bwlch of Mynydd Llangynidr |
The route toward the
summit seemed pathless from this approach but never proved difficult as when
height was gained we came across sheep tracks criss-crossing the open land with
many heading up toward our next objective.
I looked back occasionally whilst on the ascent and the thin ribbon of
road looked almost river like with the high mountains of Pen y Fan and the
Beacons forming a backdrop.
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| Mark on the ascent of Mynydd Llangynidr |
As we popped over the
penultimate moorland ridge the large summit cairn came into view, its name is
appropriately Garn Fawr, and it is Bronze Age and approximately 20 metres in
diameter. Its inner structure has now
been fashioned as a wind shelter with one or two others joined at its side, but
the majority of the base of the cairn seems undisturbed. This ancient cairn along with many of its
counterparts positioned on similar hill tops would have been for burial.
Approaching the cairn I picked
out land at its base that looked the highest, and then proceeded to walk around
its base, after inspecting the base of the cairn from a lower position the land
that I had judged to be the highest, remained so. Again the Trimble was positioned on the top
of my rucksack for it to gain elevation, a measurement offset of 0.43m was
recorded and it quickly attained the 0.1m accuracy before data can be
logged. Once it was gathering data I
fancied a butty, banana and a drink, and felt rather abject when I realised
they were still in my rucksack – ho hum!
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| Gathering data from the highest bit of land at the base of the large ancient cairn at the summit of Mynydd Llangynidr |
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| Looking down from the top of the ancient cairn to the Trimble set-up position |
As the last of the 300
points of data were collected I approached the equipment, switched it off,
packed it away, grabbed my rucksack and its all-important contents and sat down
for drink and food.
As we sat and ate we
discussed the complexities of the cairn and its importance in the height of
this hill and its possible dethroning from Hump status. I gave the margin of uncertainty for height
placement for the set-up position of the Trimble as 0.3m, this is relative to
the ground at the base of the cairn and not for higher ground that could be
under the cairn, this is impossible to judge so I did not try to do so. We also wondered about the height of the
cairn and our best estimate was between 3m - 5m.
Between us and the summit
of Blaen Onneu is the Chartist Cave and that’s where we headed to next. I’d only visited each of these summits once
before as single bags from their nearest roads, but had a longing to visit this
cave for a number of years.
The Chartist Cave takes
its name from the 1839 Chartist uprising and it was used to stockpile weapons
for the upcoming march by Chartist rebels on Newport in November of that
year. It is also recorded by older Welsh
names of Ogof Fawr (big cave) and Tylles Fawr (great hole). The cave entrance has a broad arch formed of
Twrch Sandstone, commonly known as Millstone Grit, which overlays the Limestone
beneath.
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| Approaching the entrance to the Chartist Cave |
A good path leads from
the top of Mynydd Llangynidr and its ancient Garn Fawr all the way to the caves
entrance where a plaque commemorates the uprising. As explained on the plaque the Chartist
uprising led to the greatest armed clash between government forces and British
people in the nineteenth century, and resulted in over 20 deaths and the last
mass treason trial undertaken in Britain.
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| The plaque on the side of the cave |
It still amazes me that
authority can dictate against the will of the people and justified wants are
battled against to the point of death and accusation of treason. It seems that some powers that be seldom
constitute justifiable change unless given an almighty great shove to do so.
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| From inside looking out |
We examined the cave and
its depths where at least two further smaller chambers disappear into darkness,
a lovely place to visit and to combine it on the same day as a visit to the
Aneurin Bevan Memorial Stones seemed rather apt.
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| The continuation of one of the small chambers |
The path beside the cave
continued all the way to the summit of Blaen Onneu, on the way we passed a
group of teenagers on their Duke of Edinburgh award scheme outing, where
overladen rucksacks and a seeming willingness not to know in which direction to
go is the order of the day.
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| Thankfully a path exists between the two summits, otherwise it would be rough going |
On the way to this
summit we looked out toward where the hill’s bwlch lay, as it’s currently
listed with c 27m of drop in the 500m Sub-Twmpau and with 28m of drop in a Sub-Dewey
list it has an outside possibility of reaching the echelons of P30 status.
The summit of Blaen
Onneu is situated about three metres from the base of its trig pillar and as
the Trimble gathered its five minutes of data I replenished my energy levels
with sustenance and took a few photographs as the late afternoon light started
to enhance the land.
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| Gathering data at the summit of Blaen Onneu |
All that now remained
was an examination of this hill’s bwlch and a long walk back on the path past
the Chartist Cave and Garn Fawr to the awaiting car. We strode off with two ten figure grid
references already input into Mark’s hand-help GPS for where I had estimated
this hill’s critical bwlch to lie. The
first of these was off the main path in an area of long grass with occasional
patches of heather giving colour to the predominant greens. Whilst Mark stood at the point of the first
ten figure grid reference I stood on lower ground between him and the summit on
the hill to hill traverse, between the two of us was an intervening bump and
away to our south looked to be much higher ground on the valley to valley
traverse. This whole area was proving
complicated to judge and there was a simple reason for it; sink holes, these
form as the land collapses into the Limestone beneath and when this occurs in
the area of a bwlch it instantly gives two possible positions on the valley to
valley traverse for where the critical bwlch may be positioned. What we faced was a land consisting of one
large sink hole with another to our north and as we really got to grips with
judging and surveying the land there were another two to our south.
We had to get surveying
as our original plan was to do another walk after this one and that possibility
was quickly receding. I joined Mark and
set the Trimble up and waited until the o.1m accuracy appeared on its screen
and then pressed ‘Log’, as the Trimble gathered data Mark examined the land
where I had previously been standing, which by eye was definitely lower than
where the Trimble was now set up.
However, once five minutes of data were gathered Mark was striding off
toward where the second ten figure grid reference was directing him to go and
telling me not to survey the point where I had originally stood just yet, as
the lay of land was much more complicated that I had first judged.
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| The first of three points surveyed for the critical bwlch of Blaen Onneu |
The second point that I
had estimated for the position of the critical bwlch of Blaen Onneu lay to the
south in a morass of green tussock grass that stretched for an age, all uniform
and delightfully wild. The margin of
uncertainty for height placement would be large in such a place and I grabbed a
figure out from the wilderness and scribbled 0.8m down in my note book as the
Trimble started to collect its data.
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| The second of three points surveyed for the critical bwlch of Blaen Onneu |
Back to our north I kept
looking toward the ground where I had first stood and knew that this also
needed to be Trimbled, so when the equipment was packed away we headed back and
Mark then pointed out yet another sink hole between the point where I had first
stood and the land further north, by now time was of the essence as we had a
two hour drive to get back to Welshpool and Mark a further hour’s drive to
Mold, our hopes of another walk after this one were now just about shelved.
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| Heading back out of the great expanse of grassland toward where the third bwlch survey took place, which is conveniently placed directly above Mark's head in this photograph |
As Mark patiently waited
in the evening sunshine I took a third bwlch data set and as the Trimble
gathered data I looked at the land beyond the sink hole to the north and
visually judged this to be lower and therefore as it was on the valley to
valley traverse it did not need surveying.
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| The third and last point surveyed for the critical bwlch of Blaen Onneu |
Happy with what we had
done we set off back on the path toward the cave and the large cairn, this time
we kept to the path as it bi-passed the summit of Mynydd Llangynidr to its
south and continued on its downward route to the rough paved road below.
By the time we reached
the car it was 7.20pm and the distance we had to travel back home dictated that
there would not be another walk today.
All that remained was to get boots off, change and drive back home, or
so we thought.
As I got changed a large
quad bike roared down the gravelled road and I flagged the driver down thinking
he may be a local farmer who I could ask about locally known names for the
hills, the driver was Greg Owen from Rhymney and he asked us if we planned on
driving down the road and said that if we did, we couldn’t, as the barrier was
now locked. We didn’t even realise that
a barrier existed, Greg proved a great help as within a few minutes I was on
the back of his quad bike and we were roaring up the track to the top quarry
just under the summit of the hill that many list as Cefn yr Ystrad to ask the
security guard for the key to unlock the barrier.
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| Greg Owen - a saviour in time of need |
The security guard
didn’t have the key and directed us to the bottom quarry where another security
guard would be able to help us. We
roared back down the hill to the car where Mark was patiently waiting, soon we
were following Greg as he led the way on his bike and indicated where we should
go toward the lower quarry. Greg had
been a great help and without him we may have ended up sleeping in the car
until the early hours when the barrier was unlocked.
I parked the car next to
a locked gate at the lower quarry, which was still high on the slopes of Mynydd
Llangynidr and went in search of the security guard, it took me a few minutes
to find him, but when I did he was very helpful, and as he couldn’t drive he came
down in the car with Mark and I to unlock the barrier, only for him to then
walk back up the hill to man his post, we offered a small payment for his help
which he politely declined.
It had been another good
day on the hill with one or two interesting survey results to look forward to,
with the ending to the last of our walks resulting in the kindness of two local
people to get us out of our predicament.
For those heading up the
Trefil road the barrier is locked at 5.00pm and unlocked at 6.30am. There are on-line write ups stating that the
barrier remains locked at weekends.
Survey Result:
Mynydd Llangynidr
Summit Height: 557.6m (converted to OSGM15)
Summit Grid Reference: SO 12343 15135
Bwlch Height: 455.2m (converted to OSGM15)
Bwlch Grid Reference: SO 11034 15118
Drop: 102.4m (Hump status confirmed)
Dominance: 18.37%
Dominance: 18.37%
Blaen Onneu
Summit Height: 541.0m (converted to OSGM15)
Summit Grid Reference: SO 14700 15933
Bwlch Height: 515.6m (converted to OSGM15)
Bwlch Grid Reference: SO 14039 15155
Drop: 25.4m (500m Sub-Twmpau status confirmed)
Dominance: 4.70%
Dominance: 4.70%
For further details please
consult the Trimble survey spreadsheet click {here}
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