Monday, 1 December 2014

Mapping Mountains – Trimble Surveys – Pen Llŷn



24.11.14  Garn Boduan (SH 312 393, bwlch only), Moel Gwynus (SH 340 422), Moel Tŷ-gwyn (SH 331 416), Mynydd Nefyn (SH 325 406), Carreglefain (SH 324 410) and Gwylwyr (SH 320 412)       
  
Carreglefain (SH 324 410)
On the northern coast of the Llŷn is a compact group of five P30’s, all are within the 200m height band with three of the five hills forming a small ridge with, considering their height, impressive rock faces.  The five hills are positioned mid-way between the small communities of Llithfaen and Nefyn.

I’d wanted to visit these hills for a number of years and with the weather forecast predicting a settled day with the probability of increased cloud late in the afternoon, I decided that it was a perfect day to visit. 

Having studied the Ordnance Survey map and driven a Google car on the B4417 the previous evening I had devised a route between the hills and found a parking spot.  However, one thing I had not done was study the map contouring in any great detail and as I drove west and approached these hills I suddenly dropped downhill and continued around the base of one of the hills.  My devised route relied upon surveying the most north-easterly of the critical bylchau which is situated north of the summit of Moel Gwynus, and then driving to the parking spot I had found the previous evening before heading up the aforementioned hill.  This would save time and a walk on the road.

Having driven downhill I wondered where the first bwlch was that I wanted to survey, I doubled back and tried to equate the landscape I was looking at with the image on the map.  I found a spot to pull off the road and walked down a track into a field, found the critical bwlch between two of the hills, set the Trimble up and gathered five minutes of data.  During this the early morning sun cast beautiful radiant light from the east highlighting the late autumnal colour.

Gathering data at the first bwlch of the day between Moel Gwynus and Moel Tŷ-gwyn
Once this bwlch had been surveyed I drove to the parking spot on a dead end minor road just off the B road at SH 329 421, where a number of cars can be parked on a gravelled area close to the start of a footpath heading north into land owned by the National Trust.

As I left my car and walked up the narrow road to the B road I had chance to study the map and soon realised that I had just surveyed the connecting bwlch between Moel Tŷ-gwyn and Moel Gwynus which is the critical bwlch for Garn Boduan, a hill to the west.  This was not the bwlch I planned to first survey, this being the connecting bwlch between Moel y Gwynus and a 300m hill further north.  This meant I had a walk up the road to the northerly bwlch if I wanted to continue with surveying every summit and bylchau en route between the five hills I planned to visit.  As the forecast was good and as it was only just past 9.00am I decided that time would probably allow an approach from the east, which would also mean that the low sun would be at my back for the majority of the walk and not directly into my eyesight for hours on end.

I tried hitching a lift with a number of cars as they sped past but eventually decided that a walk next to and on the road was rather enjoyable and soon I arrived at the northerly bwlch.  This is given a 195m spot height on the Ordnance Survey 1:25,000 map which is positioned on the road, with the enlarged Geograph map giving a 194m height on the same road and a 192m height in an adjacent field.  Once at the area of the bwlch I walked on the road and judged that the critical bwlch is positioned in the field to my left, I clambered over the adjacent fence and wandered around the closely cropped sheep grazed field and picked a spot and gathered five minutes of data.  During the data gathering I had time to walk up the field for a view down onto the area of the bwlch and decided to gather another data set a few metres north-westward of the first Trimble position.  Thankfully no passing farmer stopped during this process and once satisfied that I had two data sets to compare height and position I headed back to the road and a gate that gave access onto the lower slopes of Moel Gwynus.

Moel Tŷ-gwyn (left) and Carreglefain (central) from the top of the road leading to the second bwlch survey
Hills positioned next to coastal waters give a fulfilling experience and one that is different, but hard to quantify, when compared to hills positioned inland and today’s walk had already started to give wide, open views back towards the hills of Yr Eifl with Garn Ganol central and aloof symmetrised between Garnfor to its left and Tre’r Ceiri to its right, a fine figurement of hill architecture. 

As I gained the high point of Moel Gwynus the views south-westward opened up with the rusted colour etched on the triad of hills including and adjacent to Carreglefain that all looked welcoming in the morning light, these were framed against the foreground by the rounded shape of Moel Tŷ-gwyn; my next hill.

Gathering data at the summit of Moel Gwynus with Garnfor, Garn Ganol and Tre'r Ceiri in the background

Carreglefain framed by Moel Tŷ-gwyn in the foreground

Gathering data at the summit of Moel Gwynus
Once summit data were collected I headed down the slopes toward the previously surveyed bwlch and proceeded down the track toward another fence positioned on a high earthen embankment.  Once over and through a gate a path led me up to the high point of the hill.  The 217m spot height appears just on the western side of the summit wall on the Geograph map whilst other OS maps have it positioned just on the eastern side of the wall.  I found the ground on the eastern side to be slightly higher.

The next objective - Moel Tŷ-gwyn
The Trimble was set up and I stood and looked back toward Moel Gwynus with Garn Ganol beyond, ahead lay the next three hills with an intervening bwlch that looked as if it may be in someone’s field or even worse, in a living room.

(L-R) Garnfor, Garn Ganol and Moel Gwynus
The hills of Yr Eifl in the background with the summit of Moel Tŷ-gwyn on the right of the stone wall
It was only a short distance down to the connecting bwlch which is named Bwlch Gwynt on the map, and approaching it from above helped in assessing the lay of land.  It was as I had suspected; positioned in a field close to a public footpath.  I knocked on the front door of a house that looked out onto the field as an attentive dog wagged its way over for friendship.  No one was in so I opened a gate and wandered into the field and quickly judged the spot to gather data from, took a couple of photos and wandered from the field through another couple of gates and back onto the footpath.

Gathering data at the critical bwlch of Moel Tŷ-gwyn
A track led past more houses leading to a path which gave easy access onto the next hillside.  By now the sun had been overtaken by a bank of cloud that dulled the colour.  The first of the three compact hills I visited has an accompanying small quarry and is positionally unnamed on current Ordnance Survey maps and therefore I made enquiries at two houses, however the name Mynydd Nefyn appears on current maps to the south-west of this hill and importantly this name is positioned on older Ordnance Survey maps taking in this hill's summit.

The path had recently been used by cattle and was a little churned and muddy, but it gave easy access to a solid wall which had a stone slabbed step inserted indicating a crossing place.  Once on the other side a green path led upto the remains of the quarry workings and the steepening sides of the upper part of the hill.  Once I gained the summit of the hill the view southward opened up with slithers of sea illuminated by sun cast out from behind cloud, the Llŷn is a magical place with an atmosphere its own, in some aspects more reminiscence of many parts of Ireland than its native country.

I gathered data from two potential highest points on this hill, with the furthest south being my favoured for the summit position.  The first was on grass and the second on a small pointed rock which I surveyed with the aid of my rucksack which I lay at its base and nestled the Trimble on it aligned to the rock’s high point.  This was similar to what Aled had suggested doing at the summit of Ynys Berfedd two days ago, the only difference being was I did not have to clip the Trimble to the rucksack this time as it wasn’t perched over a dramatic drop.

The first summit position for Mynydd Nefyn came to 255.40m at SH 32481 40693
The view from the first set up position on Mynydd Nefyn to the second summit
The second summit position for Mynydd Nefyn came to 255.71m at SH 32515 40646
As data were gathered the sun started to break past the cloud bank and colour etched the land with dark shadowed patches bringing depth to the landscape.  This colour was dramatically prevalent as I left the summit and headed toward the connecting bwlch with Carreglefain.

The connecting bwlch had bright green grass on one side and the welcome rusted colour of bracken on another, all neatly separated by a stone wall, all illuminated by afternoon sunlight.  Occasionally the time the Trimble gathers data allows one to stop, listen and look and soak in the ambiance of being on the hill.  Small inconsequential things can give serenity, and as I stood beside the stone of wall and looked at the colour wash of green and rusted growth I was contentedly transported to a wistful place of happiness.  This was broken as the allotted five minute data gathering duration was reached.

The critical bwlch of Pt. 256m
Ahead was a wall of colour and rock, this is the southern face of Carreglefain which rising up as a solid cliff with a shapely profile rose into a sky of deep blue, a wonderful sight.  I took many photos as I approached the cliff, this had been colour dubdued when heading toward the seemingly unnamed hill but it was now cast resplendently on show.

A marvellous hill - Carreglefain
Splitting the cliff and accompanying boulders on its eastern side is a brackened slope which gave easy access to the top, this when reached affords a marvellous viewpoint with a neatly shaped small cairn positioned just below the high point.  Once the Trimble was set up I stood back and soaked in the summit and the land I had walked on. 

The cliff face from the brackened slope
Gathering data at the summit of Carreglefain
To the north-west the shapely profile of Gwylwyr, the last hill of the day, stood out above its coastal realm.  From this direction its slopes looked like they were covered in bracken.  To the west was Nefyn, nestled in the lowlands of field and coastal beauty with the slender finger of land above Porth Dinllaen heading confidently out to sea.

(L-R) Nefyn, Porth Dinllaen and Gwylwyr
Only one hill and two bylchau remained to survey and once down from the rocky summit of Carreglefain I found a narrow path heading down toward the connecting bwlch with Gwylwyr.  This path had heather, bracken and the first signs of gorse beside it, a foreteller of things to come.

The next bwlch is positioned in a land of closely cropped green field interspersed with bulbous gorse growth, once Trimbled I headed toward another stone wall, crossed it and started up the slopes of Gwylwyr.

Gathering data at the critical bwlch of Gwylwyr
Unfortunately these lower slopes consist of gorse, heather, bracken, large rocks and dreaded brambles.  Progress suddenly became very slow with brambles and gorse and rock giving a sting in the tail of an excellent walk.  Slowly I stumbled through the rugged stuff and once the bramble ceased I headed for the heather to give me an easier passage to the top.

The high point of Gwylwyr is positioned at the far point of its rocky crest and gives excellent coastal views.  It proved an appropriate summit to end on with views east to the higher peaks of Yr Eifl and views west to the continuing coastland.

Gathering data at the summit of Gwylwyr
Gravity helped my downward route being a wee bit easier but the brambles and gorse still proved unwelcome.  Once over the wall I joined a path heading down to the farm of Hendy where another knock on the door was hoped to find a name for the 256m summit next to the quarry.  Again, no one was in so I re-joined the narrow lane and walked down into Pistyll and back on the B road to my awaiting car.

I then drove into Nefyn and up a steep narrow road toward the last survey of the day which was at the critical bwlch of Carreglefain.  I parked at a convenient spot next to a small row of cottages, walked up a track and knocked on the door of the house next to the field where I judged the critical bwlch lay.  The occupant had only been in the house a couple of weeks but said that she was sure the local farmer would not mind.  So as the last light of the day slowly ebbed away I stood in a field of sheep as the Trimble gathered its 13th data set of the day.  A great walk with excellent views on lovely hills.     



Survey Result:


Garn Boduan 

Bwlch Height:  103.5m (converted to OSGM15)

Bwlch Grid Reference:  SH 33645 41879

Drop  175m

Dominance:  62.72%




Moel Gwynus 

Summit Height:  236.1m (converted to OSGM15)
   
Summit Grid Reference:  SH 34066 42285

Bwlch Height:  192.7m (converted to OSGM15)

Bwlch Grid Reference:  SH 34384 42935

Drop  43.4m

Dominance:  18.38%




Moel Tŷ-gwyn 

Summit Height:  216.2m (converted to OSGM15)
   
Summit Grid Reference:  SH 33186 41692

Bwlch Height:  160.8m (converted to OSGM15)

Bwlch Grid Reference:  SH 32842 41450

Drop  55.5m

Dominance:  25.65%





Mynydd Nefyn 

Summit Height:  255.7m (converted to OSGM15)
   
Summit Grid Reference:  SH 32515 40646

Bwlch Height:  210.8m (converted to OSGM15)

Bwlch Grid Reference:  SH 32443 40926

Drop  44.9m

Dominance:  17.55%


 

Carreglefain 

Summit Height:  260.7m (converted to OSGM15)
   
Summit Grid Reference:  SH 32421 41054

Bwlch Height:  130.1m (converted to OSGM15)

Bwlch Grid Reference:  SH 31677 39852

Drop  130.6m

Dominance:  50.08% (Lesser Dominant reclassified to Dominant status confirmed)


 


Gwylwyr 

Summit Height:  236.7m (converted to OSGM15)
   
Summit Grid Reference:  SH 32010 41255

Bwlch Height:  198.9m (converted to OSGM15)

Bwlch Grid Reference:  SH 32207 41117

Drop  37.8m

Dominance:  15.98%







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