Golden moorland of Blaenpedol - geograph

is a hill in the

Brecon Beacons National Park Brecon Beacons National Park, officially named Bannau Brycheiniog National Park (), is a National parks of the United Kingdom, national park in Wales. It is named after the Brecon Beacons (), the mountain range at its centre. The national park ...

() in the county of

Carmarthenshire Carmarthenshire (; or informally ') is a Principal areas of Wales, county in the South West Wales, south-west of Wales. The three largest towns are Llanelli, Carmarthen and Ammanford. Carmarthen is the county town and administrative centre. ...

Wales Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...

. Its summit sits atop a plateau-like ridge at above sea level and is marked by one of the three huge

cairn A cairn is a human-made pile (or stack) of stones raised for a purpose, usually as a marker or as a burial mound. The word ''cairn'' comes from the (plural ). Cairns have been and are used for a broad variety of purposes. In prehistory, t ...

s which give the mountain its name. The main ridge leads southwest towards the subsidiary top of Tair Carn Isaf ("Lower Three Cairns", ), which hosts further cairns. The summit of this top lies at , whilst a

trig point A triangulation station, also known as a trigonometrical point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity. The station is usually set up by a map ...

just to its southwest lies at a height of . To the south of the main ridge lies the subsidiary peak of Drysgol which reaches a height of .

Geology and drainage

To the south is the

Amman Valley Amman Valley may refer to: *The valley that hosts Downtown Amman *The valley of the River Amman * Amman Valley Hospital *Amman Valley Railway * Amman Valley Railway Society *Amman Valley School Ysgol Dyffryn Aman ( Amman Valley School) is a bilin ...

into which flow the streams of Nant Pedol and Nant-y-ffin or Berach whilst the Nant Gwythwch drains westwards into the

River Loughor The River Loughor () () is a river in Wales which marks the border between Carmarthenshire Carmarthenshire (; or informally ') is a Principal areas of Wales, county in the South West Wales, south-west of Wales. The three largest towns ar ...

. 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 River Loughor and

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 Cenne ...

. The summit plateau is formed from blocks of the Twrch Sandstone (formerly the 'Basal Grit') of the

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 geograp ...

(former 'Millstone Grit Series') deposited during the

Carboniferous period The Carboniferous ( ) is a geologic period and system of the Paleozoic era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the Permian Period, Ma. It is the fifth and penultimate perio ...

. Whilst the general dip of the rock

strata In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...

is to the south, there are areas which have foundered due to the presence of the soluble limestone not far beneath the surface.British Geological Survey 1:50,000 map sheet 230 'Ammanford'

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 The Beacons Way (Welsh: Ffordd y Bannau) is a waymarked long distance footpath in the Brecon Beacons National Park, Wales. It is a linear route which runs for east to west through the National Park, and passes many of the most important landmar ...

route from

Llangadog Llangadog () is a village and community in Carmarthenshire, Wales, which also includes the villages of Bethlehem and Capel Gwynfe. A notable local landscape feature is Y Garn Goch with two Iron Age hill forts.The Welsh Academy Encyclopedia of ...

Abergavenny Abergavenny (; , , archaically , ) is a market town and Community (Wales), community in Monmouthshire, Wales. Abergavenny is promoted as a "Gateway to Wales"; it is approximately from the England–Wales border, border with England and is loca ...

runs along the northern flanks of Tair Carn Uchaf.

External links

images of Tair Carn Uchaf & surrounding area on the Geograph website

References

{{coord, 51.8397, -3.8977, type:mountain_region:GB, display=title Mountains and hills of Carmarthenshire Black Mountain (range)