Tair Carn Uchaf
Encyclopedia
Tair Carn Uchaf is a hill in the Brecon Beacons National Park in the county of Carmarthenshire
, southwest Wales
. Its summit sits atop a plateau-like ridge at 482 metres (1,581.4 ft) above sea level and is marked by one of the three huge cairn
s which give the mountain its name.
The main ridge leads southwest towards the subsidiary top of Tair Carn Isaf ("Lower Three Cairns", 51.8344°N 3.9113°W), which hosts further cairns. The summit of this top lies at 460 metres (1,509.2 ft), whilst a trig point
just to its southwest lies at a height of 459 metres. To the south of the main ridge lies the subsidiary peak of Drysgol which reaches a height of 393 metres (1,289.4 ft).
. Rainwater falling on the hill's northern slopes is likely to spend part of its journey underground on account of the band of Carboniferous Limestone
which sweeps across this area from east to west. Northward drainage is ultimately into the Afon Llwchwr and Afon Cennen
.
The summit plateau is formed from blocks of the Twrch Sandstone (formerly the 'Basal Grit') of the Marros Group
(former 'Millstone Grit Series') deposited during the Carboniferous period. Whilst the general dip of the rock strata
is to the south, there are areas which have foundered due to the presence of the soluble limestone not far beneath the surface.
to Abergavenny
runs along the northern flanks of Tair Carn Uchaf.
Carmarthenshire
Carmarthenshire is a unitary authority in the south west of Wales and one of thirteen historic counties. It is the 3rd largest in Wales. Its three largest towns are Llanelli, Carmarthen and Ammanford...
, southwest Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
. Its summit sits atop a plateau-like ridge at 482 metres (1,581.4 ft) above sea level and is marked by one of the three huge cairn
Cairn
Cairn is a term used mainly in the English-speaking world for a man-made pile of stones. It comes from the or . Cairns are found all over the world in uplands, on moorland, on mountaintops, near waterways and on sea cliffs, and also in barren desert and tundra areas...
s which give the mountain its name.
The main ridge leads southwest towards the subsidiary top of Tair Carn Isaf ("Lower Three Cairns", 51.8344°N 3.9113°W), which hosts further cairns. The summit of this top lies at 460 metres (1,509.2 ft), whilst a trig point
Trig point
A triangulation station, also known as a triangulation pillar, trigonometrical station, trigonometrical point, trig station, trig beacon or trig point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity...
just to its southwest lies at a height of 459 metres. To the south of the main ridge lies the subsidiary peak of Drysgol which reaches a height of 393 metres (1,289.4 ft).
Geology and drainage
To the south is Cwm Aman into which flow the streams of Nant Pedol and Nant-y-ffin or Berach whilst the Nant Gwythwch drains westwards into the Afon LlwchwrRiver Loughor
The River Loughor in Carmarthenshire, Wales has its source at an underground lake at the Black Mountain. It flows past settlements like Ammanford and Hendy in Carmarthenshire and Pontarddulais in Swansea. The river divides Carmarthenshire from Swansea for much of its course and it separates Hendy...
. Rainwater falling on the hill's northern slopes is likely to spend part of its journey underground on account of the band of Carboniferous Limestone
Carboniferous limestone
Carboniferous Limestone is a term used to describe a variety of different types of limestone occurring widely across Great Britain and Ireland which were deposited during the Dinantian epoch of the Carboniferous period. They were formed between 363 and 325 million years ago...
which sweeps across this area from east to west. Northward drainage is ultimately into the Afon Llwchwr and Afon Cennen
Afon Cennen
The Afon Cennen is a river in the county of Carmarthenshire, south Wales. It rises on the northern slopes of the Black Mountain to the east of the summit of Tair Carn Uchaf and flows north to Blaencennen Farm, then westwards past Carreg Cennen Castle, continuing through the village of Trap where it...
.
The summit plateau is formed from blocks of the Twrch Sandstone (formerly the 'Basal Grit') of the Marros Group
Marros Group
The Marros Group is the name given to a suite of rocks of Namurian age laid down during the Carboniferous period in South Wales. These rocks were formerly known as the Millstone Grit Series but are now distinguished from the similar but geographically separate rock sequences of the Pennines and...
(former 'Millstone Grit Series') deposited during the Carboniferous period. Whilst the general dip of the rock strata
Stratum
In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...
is to the south, there are areas which have foundered due to the presence of the soluble limestone not far beneath the surface.
Access
The hill is open country so walkers can roam across it at will. There are public footpaths along its southern margin and a long bridleway crosses the moors to the east of the hill. two minor roads cross its western flanks. The Beacons Way route from LlangadogLlangadog
Llangadog is a community located in Carmarthenshire, Wales, which includes the villages of Llangadog, Bethlehem and Capel Gwynfe. A notable local landscape feature is Y Garn Goch with two Iron Age hill forts....
to Abergavenny
Abergavenny
Abergavenny , meaning Mouth of the River Gavenny, is a market town in Monmouthshire, Wales. It is located 15 miles west of Monmouth on the A40 and A465 roads, 6 miles from the English border. Originally the site of a Roman fort, Gobannium, it became a medieval walled town within the Welsh Marches...
runs along the northern flanks of Tair Carn Uchaf.