Mynydd Machen or Machen Mountain is a 362-metre-high (1,188 ft) hill lying between the town of Risca and the village of Machen in Caerphilly County Borough in south Wales. Its summit is crowned by a trig point and a mast.
Mynydd Illtud is an extensive area of common land near Libanus, Powys, Wales, located in the Brecon Beacons National Park and some three miles south-west of Brecon. The common is an undulating plateau lying between 330 and 370 metres above sea level. Its highest points are 381 metres (1,250 ft) at Allt Lom and 367 metres (1,204 ft) at Twyn y Gaer trig point overlooking the valley of the River Usk. Twyn y Gaer is the site of an Iron Age hill fort.
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 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.
Y Garn Goch is a hill in the Brecon Beacons National Park in the east of Carmarthenshire, Wales. The name means the 'red cairn'. It lies near the village of Bethlehem, three miles southwest of Llangadog and four miles east of Llandeilo on the southern side of the broad Towy Valley. It is also commonly known as either Garn Goch or Carn Goch. Current owners and land managers are the Brecon Beacons National Park Authority.
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.
Mynydd Carn-y-cefn is the name given to the broad ridge of high ground between the Ebbw Vale and the valley of the Ebbw Fach in the Valleys region of South Wales. It lies within the county borough of Blaenau Gwent, formerly Monmouthshire.
Cefn Manmoel is the name given to the broad ridge of high ground between the Sirhowy Valley and Ebbw Vale in the Valleys region of South Wales. It straddles the boundary between the unitary areas of Caerphilly and Blaenau Gwent.
Mynydd Merthyr is a broad ridge of high ground between Taff Vale and the Cwm Cynon in the Valleys region of South Wales. It forms the boundary between the unitary authorities of Rhondda Cynon Taff to the west and Merthyr Tydfil to the east.
Mynydd Cilfach-yr-encil attains a height of 445m at OS grid reference SO 079033 making it the high point of the broad ridge of high ground between Taff Vale and Cwm Bargod in the Valleys region of South Wales. It lies within the County Borough of Merthyr Tydfil.
Cefn y Brithdir is the name given to the broad ridge of high ground between the Rhymney Valley and Cwm Darran in the Valleys region of South Wales. It lies within the County Borough of Caerphilly.
Mynydd Llangeinwyr is the highest hill in the county borough of Bridgend in the coalfield of South Wales. It forms a long north-south ridge between the valleys of Cwm Garw to the west and Cwm Ogwr Fawr to the east. The highest point of the ridge is the 568-metre flat dome known as Werfa which is crowned by a trig point and prominent masts. A secondary trig point is sited at a height of 530 m near to the ancient cairn of Carn-yr-hyrddod. The hill is named from the village of Llangeinor below its southern tip.
Mynydd Meio is a 322-metre-high hill in the county borough of Caerphilly in South Wales. Parts of its western slopes fall within Rhondda Cynon Taf county borough. Its eastern slopes drop away to Cwm yr Aber between Caerphilly and Abertridwr and its western slopes to the valley of the Taf. The high point is just over 200 m north of the trig point which sits at 322 metres (1,056 ft) above sea-level.
Mynydd Eglwysilan is a 355-metre-high hill in the Caerphilly county borough in South Wales 3 km to the south of Nelson and a similar distance southwest of Ystrad Mynach. To its south is Senghenydd at the head of the Aber Valley. Like neighbouring Cefn Eglwysilan, the hill is named after the hamlet of Eglwysilan 4 km to the southwest, the church here being dedicated to an obscure Saint Ilan. Remains of a linear earthwork known as Senghenydd Dyke stretch across the southern side of the hill. It is considered to mark the edge of an extensive 13th-century deer park associated with nearby Caerphilly Castle.
Cefn Gwyngul is a long broad ridge to the east of the Rhondda Fach valley in Rhondda Cynon Taf County Borough in South Wales. Its 470m high summit is marked by an ancient cairn known as Carn-y-Pigwn, on which is a more recent trig point. Much of the hill is cloaked by modern forestry plantations though its southwestern flank between Porth and Ferndale has not been coniferised. The earthworks of a Roman camp remain on the ridge at OS grid ref ST 002982.
Mynydd Twyn-glas is a sprawling 472-metre-high mountain extending into Caerphilly and Torfaen county boroughs in South Wales. It lies southwest of Pontypool, west of Cwmbran and east of Newbridge and taking the form of a rolling plateau the margins of which are defined by steep slopes, many of which are cloaked with conifer plantations. A broad shoulder extending south from the summit is known as Mynydd Maen whilst to the north is Mynydd Llwyd. The thickly afforested northern slopes of the hill drop down steeply into Cwm y Glyn.
Mynydd y Lan is a 381-metre-high flat-topped hill in Caerphilly county borough in South Wales. It falls largely within the community of Ynysddu but its northern and eastern margins are within Crosskeys community. Its largely wooded southern and eastern flanks rise steeply from the Sirhowy and Ebbw valleys respectively. A wireless transmission station is located towards the northern end of the summit plateau. The current name is a possible corruption of Mynydd y Llan, referencing the parish church of St Tudor, situated on its plateau. the church site has been occupied since the 5th century, with an early British site, being replaced by the Norman 11th century church.
Mynydd y Grug is a hill lying just west of the village of Cwmfelinfach and about 4 km to the northeast of Caerphilly in Caerphilly county borough in South Wales. Its summit was formerly at a height of around 358 m, but since the top has been covered by a large spoil heap and landscaped its height has now increased to 375 m, though some authorities take other values for the summit height. A number of ancient cairns are found along its edge overlooking the Sirhowy Valley, the slopes up from which are largely wooded.
Mynydd William Meyrick is a 535-metre-high hill straddling the boundary of Bridgend and Rhondda Cynon Taf county boroughs between the valley of the Rhondda Fawr and Ogmore Valley in South Wales. It takes the form of a broad northwest-southeast ridge with numerous broad shoulders extending to the east, south and west, each of which have different names and some of which constitute minor tops. Listed clockwise from the north these are; Mynydd Maendy, Mynydd Ton, Mynydd Bwllfa, Mynydd Pwllyrhebog, Mynydd Maes-teg, Mynydd y Gwair and Mynydd yr Aber. The summit of the entire massif is often referred to as Mynydd Ton. Its western sides are open moorland whilst its eastern sides have been afforested by the Forestry Commission.
Mynydd Allt-y-grug is a 338-metre-high hill immediately west of Ystalyfera in the county borough of Neath Port Talbot in South Wales. Its twin summits are around 400m apart. The upper part of the hill is largely covered in heather whilst conifers clothe its western slopes and gorse, bracken and bramble cover much of its rough landslide eastern side which rises above the Swansea Valley, drainage on this side flowing to the River Tawe.
