Mapping Mountains – Trimble Surveys – Yr Eifl

11.04.21  Mynydd Mawr (SH 140 258) 

Mynydd Mawr (SH 140 258) from my previous visit to the hill

The last time I visited Mynydd Mawr was in the early life of my Trimble when accompanied by Aled and Mark we visited the hill and I surveyed its summit.  On that day we chased daylight hours as this was in Decemeber 2014 and after descending the hill we walked up the adjacent Mynydd y Gwyddel.  Here we stayed watching as the last embers of daylight sank behind the blackened profile of Ynys Enlli giving a beautiful sun set. 

Watching the sun set after my previous visit to Mynydd Mawr

Today was at contrast as I was out with my brother; Bryn, touring the Llŷn and investigating its minor roads.  We had no definite destination, just to get out whilst enjoying the company that Covid had starved us of over the last year or so. 

Although we had no definite destination I had mentioned driving up Mynydd Mawr, but again we just aimed west and carried on.  By doing this we found ourselves at the base of the hill, and once here we were definitely going to aim for its summit. 

The weather conditions were also at contrast to my last visit, this as described above gave late afternoon winter light before we stood and quietly watched the sun set.  Today showers were forecast with a mixture of sleet and snow.  Before setting off we had watched large flakes of snow fall for an hour or so, cloaking near hills.  By the time I drove up the concrete access road leading to the top of Mynydd Mawr the snow had quickly thawed from this part of the world and glimmers of sun and little breeze warmed us as we got out of the car. 

The end of the concrete road

Bryn headed off toward a rocky knoll to look out to sea, whilst I scampered up to the high point of the hill.  Away to our west and out to sea huge shower clouds were massing.  Beyond Ynys Enlli, which today was greyed with slithers of spring green on its slopes, whitened winter showers were also breaking out across the sea.  But the one that dominated was blackened grey with a whitened cap; this took up much of our immediate attention.  It massed out to sea forever heading eastward directly toward the end point of the Llŷn. 

Gathering data at the summit of Mynydd Mawr during my previous visit

Same place, but different weather conditions

My brother called over as I headed his way from the summit, he just stood and pointed out to sea toward the increasingly large darkened mass of wintery shower cloud.  We knew it was heading directly toward us as by the time I had sauntered a little lower to look back up and take a few photographs, and then having re-joined Bryn, the wind had picked up and the last vestiges of sunlight were now overtaken by the darkened mass. 

Darkened shower clouds mass

We looked out to sea one last time and headed toward the car.  Driving down the concrete access road the first large drops of rain hit the windscreen.  By the time we were back on the narrow roads it was sleeting and the onward journey involved watching as huge showers took over the sky.  These were accentuated as small parts of the land were still bathed in sunshine, whilst seemingly all other land was greyed and covered in wet murk. 

It was a dramatic journey back to Nantlle watching the ever changing sky as large shower clouds obliterated the landscape.  However, it had been a good road trip and especially as we’d made the summit of Mynydd Mawr before the sleet had set in. 

 

Survey Result: 

 

Mynydd Mawr

Summit Height:  160.0m (converted to OSGM15, from previous Trimble GeoXH 6000 survey)

Summit Grid Reference:  SH 14021 25869 (from previous Trimble GeoXH 6000 survey)

Bwlch Height:  64m (spot height)

Bwlch Grid Reference:  SH 14952 26292 (spot height)

Drop:  96m (Trimble GeoXH 6000 summit and spot height bwlch)

Dominance:  60.00% (Trimble GeoXH 6000 summit and spot height bwlch)

 

 

For details on the survey of Mynydd Mawr

For details on the 3^rd visit to Mynydd Mawr

 

For further details please consult the Trimble Survey Spreadsheet