Mynydd Llangatwg

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Mynydd Llangatwg or Llangattock Mountain is a hill in the Brecon Beacons National Park in the county of Powys, south Wales. It is named from the village of Llangatwg (or 'Llangattock') which sits in the valley of the River Usk to the north of it. It is essentially an undulating plateau rising in the west to a height of 530 metres (1,740 ft) at grid reference SO171157 and in the east to a height of 529 metres (1,736 ft) at Hen Dy-aderyn / Twr Pen-cyrn. This spot is marked by a trig point. The shallow pool of Pwll Gwy-rhoc sits in a broad depression towards the northern edge of the plateau whilst a smaller pool frequently occupies a large shakehole a few hundred metres to its west. The hill forms an impressive northern scarp overlooking the Usk valley and commonly referred to as the Llangattock Escarpment. Its southern margins are more subdued. Its eastern end is defined by the drops into the Clydach Gorge. Beyond the B4560 to the west the hill merges with Mynydd Llangynidr which has a similar character. [1]

Brecon Beacons National Park national park in southern Wales

The Brecon Beacons National Park is one of three national parks in Wales, and is centred on the Brecon Beacons range of hills in southern Wales. It includes the Black Mountain in the west, Fforest Fawr and the Brecon Beacons in the centre and the Black Mountains in the east.

Powys Place

Powys is a principal area and county, and one of the preserved counties of Wales. It is named after the Kingdom of Powys which was a Welsh successor state, petty kingdom and principality that emerged during the Middle Ages following the end of Roman rule in Britain.

Wales Country in northwest Europe, part of the United Kingdom

Wales is a country that is part of the United Kingdom and the island of Great Britain. It is bordered by England to the east, the Irish Sea to the north and west, and the Bristol Channel to the south. It had a population in 2011 of 3,063,456 and has a total area of 20,779 km2 (8,023 sq mi). Wales has over 1,680 miles (2,700 km) of coastline and is largely mountainous, with its higher peaks in the north and central areas, including Snowdon, its highest summit. The country lies within the north temperate zone and has a changeable, maritime climate.


Looking south east across Mynydd Llanagatwg from Ty Aderyn with periglacial boulder stream in foreground. (November 2005) View across Mynydd Llangatwg - - 275832.jpg
Looking south east across Mynydd Llanagatwg from Ty Aderyn with periglacial boulder stream in foreground. (November 2005)

Particular features of note include 'The Lonely Shepherd', an isolated limestone pinnacle which stands at the eastern tip of the plateau, left there by quarryworkers who removed great quantities of the surrounding rock. A number of cairns are scattered across the hill, notably the sizeable pair which decorate the summit of Twr Pen-cyrn and which are thought to be of Neolithic age. A more recent addition to the landscape was Cairn-Mound Reservoir which once impounded the headwaters of Nant yr Hafod on the southern slopes though Welsh Water abandoned this some years ago and its bed has revegetated, though the embankment remains. A couple of gas pipelines have been laid across the mountain and their courses can be traced variously by fences, vegetation changes and marker poles.

The Neolithic, the final division of the Stone Age, began about 12,000 years ago when the first development of farming appeared in the Epipalaeolithic Near East, and later in other parts of the world. The division lasted until the transitional period of the Chalcolithic from about 6,500 years ago, marked by the development of metallurgy, leading up to the Bronze Age and Iron Age. In Northern Europe, the Neolithic lasted until about 1700 BC, while in China it extended until 1200 BC. Other parts of the world remained broadly in the Neolithic stage of development, although this term may not be used, until European contact.

Dŵr Cymru Welsh Water (DCWW) is a not-for-profit company which supplies drinking water and wastewater services to most of Wales and parts of western England.


Mynydd Llangatwg is formed from a layer cake of Palaeozoic Era sandstones and limestones which dip gently southwards into the South Wales Coalfield basin. Imposing cliffs of Carboniferous Limestone occur along the northern escarpment and this rock underlies the entire hill and hosts the extensive cave systems which lie beneath it, notably those of Ogof y Daren Cilau and Ogof Agen Allwedd. These two systems are amongst the longest in Britain. The plateau is formed from coarse sandstones ('gritstones') also dating from the Carboniferous Period and which have foundered in many places as the underlying limestone has dissolved over millennia. The sandstone forming low secondary scarps above the main northern and eastern escarpments is the frequently conglomeratic Twrch Sandstone often still referred to by its earlier name, the Basal Grit. In contrast, the more poorly exposed sandstone forming the high ground of the centre of the hill is the lowermost Westphalian age Farewell Rock which marks the base of the South Wales Coal Measures. Sections of the hill have a pock-marked appearance due to the dozens of shakeholes in its surface arising from the presence of the limestone beneath the sandstone cover. [2]

South Wales Coalfield

The South Wales Coalfield is a large region of south Wales that is rich in coal deposits, especially the South Wales Valleys. It supported a large part, but not all, of the coal industry in Wales.

Carboniferous Limestone

Carboniferous Limestone is a collective term for the succession of limestones occurring widely throughout Great Britain and Ireland that were deposited during the Dinantian Epoch of the Carboniferous Period. These rocks formed between 363 and 325 million years ago. Within England and Wales, the entire limestone succession, which includes subordinate mudstones and some thin sandstones, is known as the Carboniferous Limestone Supergroup.

Ogof y Daren Cilau cave in United Kingdom

Ogof y Daren Cilau is one of several cave systems in the Llangattock escarpment near Crickhowell in south Powys, Wales. The cave was discovered in 1957 and is one of the longest cave systems in the country.

Quarries and tramways

The greater part of the length of the northern escarpment is scarred by limestone quarries which operated for much of the nineteenth century. The rock was removed by means of a series of tramroads or tramways which linked north via steep inclines to a wharf on the Monmouthshire and Brecon Canal at Llangattock and south to Brynmawr and the ironworks at Nant-y-glo by two tramroads which contoured the eastern end of the hill. The upper tramway which dates from the start of the nineteenth century, runs south from Pant y Gilwern and Daren Disgwylfa and then west around the head of Cwm Clydach. It is now a grassy footpath providing easy walking through otherwise rough terrain. The lower tramway was constructed in 1828-30 and has since been converted to a public road. Both tramroads had several branches to serve individual quarries along the escarpment. Both the Twrch Sandstone and Farewell Rock have been quarried on a small scale in the past alongside the B4560 Beaufort Road with larger quarries in the latter once operating near the hill's southwestern corner.


Wagonways consisted of the horses, equipment and tracks used for hauling wagons, which preceded steam-powered railways. The terms plateway, tramway and dramway were used. The advantage of wagonways was that far bigger loads could be transported with the same power.

Tramway (industrial) type of industrial railway

Tramways are lightly laid railways, sometimes worked without locomotives. The term is not in use in North America but in common use in the United Kingdom, and elsewhere, where British Railway terminology and practices had large influences on management practices, terminology, and railway cultures such as Australia, New Zealand, and those parts of Asia that consulted with British experts when undergoing modernization. In New Zealand, they are commonly known as bush tramways, while in parts of Australia where American experts were influential, the term is less common. They generally do not carry passengers, although staff may make use of them, either officially or unofficially—and are often not meant to be permanent.

Monmouthshire and Brecon Canal network of canals in South Wales

The Monmouthshire and Brecon Canal is a small network of canals in South Wales. For most of its currently (2018) navigable 35-mile (56 km) length it runs through the Brecon Beacons National Park, and its present rural character and tranquillity belies its original purpose as an industrial corridor for coal and iron, which were brought to the canal by a network of tramways and/or railroads, many of which were built and owned by the canal company.


The B4560 road from Garnllydan to Llangynidr cuts across the high moorland and offers the easiest access to the hill and to Mynydd Llangynidr to its west. The hill is mapped as open country and therefore freely available for walkers to roam at will. There are few defined paths though a public footpath crosses from north to south passing just east of the top known as Twr Pen-cyrn. The former tramways mentioned above also provide easy level access around the margins of the hill.

Llangynidr village in the county of Powys, Wales

Llangynidr is a village, community and electoral ward in Powys, Wales, about 4 miles (6.4 km) west of Crickhowell and 9 miles (14.5 km) south-east of Brecon. The River Usk flows through the village as does the Monmouthshire and Brecon Canal. It is in the historic county of Brecknockshire.

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Ogof Craig a Ffynnon

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The Clydach Gorge is a steep-sided valley in south-east Wales down which the River Clydach flows to the River Usk. It runs for 5.6 km from the vicinity of Brynmawr in Blaenau Gwent eastwards and northeastwards to Gilwern in Monmouthshire. The Gorge was one of the first locations in the region to be industrialised though it still retains its natural environment. It has long been an important transport corridor between Abergavenny and the lowlands of Monmouthshire and the northeastern quarter of the South Wales Coalfield. It is now exploited by the A465 Heads of the Valleys trunk road which runs between Abergavenny and Swansea and which serves the Heads of the Valleys sub-region.

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Mynydd Llangynidr is a mountain in the Brecon Beacons National Park largely in the county of Powys, south Wales. Its southern slopes extend into the northernmost parts of the county borough of Blaenau Gwent. It is named from the village of Llangynidr which sits in the valley of the River Usk to the north of it. It is essentially an undulating plateau rising in the west to a height of 557m at Garn Fawr at OS grid ref SO 123151. A secondary high point is achieved at a point marked by a trig point at SO 147159. To the north the hill overlooks the valleys of Dyffryn Crawnon and Cwm Claisfer, themselves tributary valleys of the Usk. The shallow upper valley of the Ebbw River reaches into the plateau in the southeast whilst the upper reaches of the Sirhowy Valley and its tributary the Nant Trefil define its western margins. A further tributary, the Nant Milgatw, reaches in from the south whilst the sharp edge of Rassau Industrial Estate also defines a part of its southern margin. Passing east across the B4560, the hill merges with Mynydd Llangatwg which has a similar character.

Trefil village in Wales

Trefil is a small village in the county borough of Blaenau Gwent, south Wales. It lies at the top of the Sirhowy Valley, three miles northwest of Tredegar. The boundary of the Brecon Beacons National Park lies one mile to the north of the village.

Garreg Las mountain in United Kingdom

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Foel Fraith mountain in United Kingdom

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Mynydd-y-glog is a hill just east of the village of Penderyn in the northern corner of the county borough of Rhondda Cynon Taff in south Wales. It lies within the Brecon Beacons National Park and Fforest Fawr Geopark. Its summit plateau rises to a height of 389m / 1277 ft at OS grid ref SN 982088, a spot marked by a trig point. To its north lies the partly dry valley of Pant Sychbant which forms the eastern extension of Cwm Cadlan. Its southern slopes are drained by various streams which feed into the Afon Cynon.

Penmoelallt or Onllwyn is a hill in the northern part of the county borough of Rhondda Cynon Taff in south Wales. It lies within the Brecon Beacons National Park and Fforest Fawr Geopark. To its east lies the deep valley of Cwm Taf and to its north a rather shallower valley in which the Nant Cadlan originates. To the west is the hill known as Mynydd-y-glog and to the south are slopes draining into the River Taff and the Afon Cynon. The hill culminates in a broken plateau with several knolls rising above the 420m contour. Its afforested nature makes it difficult to determine the precise location of its highest point but this probably lies somewhere around OS grid ref SO 003096. Older maps indicate a spot height of 1376 ft above sea level at SO 000090.

Carreg Cadno is a hill five miles northeast of Abercraf in the county of Powys, south Wales. It lies within the Brecon Beacons National Park and Fforest Fawr Geopark. Its summit at OS grid ref SN 874161 reaches a height of 538m / 1763 ft above sea level. The hill is within the Ogof Ffynnon Ddu National Nature Reserve which is owned and managed by the Countryside Council for Wales.

Llangattock (Crickhowell) village in the county of Powys, Wales

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The Brecon Forest Tramroad is an early nineteenth century tramroad, or rather a network of connecting tramroads or waggonways, which stretched across the hills of Fforest Fawr in the historic county of Brecknockshire in south Wales, UK. Its northern terminus was at the village of Sennybridge in the Usk Valley whilst its southern ends lay at Abercraf and Ystradgynlais in the upper Swansea Valley some 20 km to the south.

Gilwern Hill, Monmouthshire mountain in United Kingdom

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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 Peak District of northern England and northeast Wales by this new name.

Mynydd y Drum mountain in United Kingdom

Mynydd y Drum is a hill on the border between the county of Powys and Neath Port Talbot County Borough, south Wales. The summit of the hill is in Neath Port Talbot at 298m and lies towards the western end of a broad curving ridge, the larger part of which is in Powys. The eastern half of the hill is currently being opencasted for coal. The hill is sometimes referred to simply as The Drum.

Chartist Cave is a culturally significant cave on Mynydd Llangynidr in southern Powys, Wales. The entrance is a broad arch formed of Twrch Sandstone which overlies the Carboniferous Limestone immediately beneath.


  1. Ordnance Survey: Explorer map sheet OL13 Brecon Beacons National Park (Eastern area) ISBN   978-0-319-46741-1
  2. British Geological Survey 1:50,000 map sheet 232 'Abergavenny' & accompanying memoir

Coordinates: 51°49′25″N3°10′00″W / 51.8236°N 3.1667°W / 51.8236; -3.1667

Geographic coordinate system Coordinate system

A geographic coordinate system is a coordinate system that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are often chosen such that one of the numbers represents a vertical position and two or three of the numbers represent a horizontal position; alternatively, a geographic position may be expressed in a combined three-dimensional Cartesian vector. A common choice of coordinates is latitude, longitude and elevation. To specify a location on a plane requires a map projection.