Crug Hywel is a flat-topped hill at the southern edge of the Black Mountains

Black Mountains, Wales

The Black Mountains are a group of hills spread across parts of Powys and Monmouthshire in southeast Wales, and extending across the national border into Herefordshire, England. They are the easternmost of the four ranges of hills that comprise the Brecon Beacons National Park, and are frequently...

 in south-east 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...

.

It rises to 451 m above sea level, from the southern flank of Pen Cerrig-calch

Pen Cerrig-Calch

Pen Cerrig-calch is a subsidiary summit of Waun Fach in the Black Mountains in the Brecon Beacons National Park in southern Powys, Wales. Its summit, at a height of 701m , is marked by a trig point...

 (701 m), and overlooks the town of Crickhowell

Crickhowell

Crickhowell is a small town in Powys, Mid Wales.-Location:The name Crickhowell is taken from that of the nearby Iron Age hill fort of Crug Hywel above the town, the Welsh language name being anglicised by map-makers and local English-speaking people...

 http://www.geograph.org.uk/photo/609494, to which it gives its name.

The summit of the hill is entirely taken up by an Iron Age

Iron Age

The Iron Age is the archaeological period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing...

 hill fort

Hill fort

A hill fort is a type of earthworks used as a fortified refuge or defended settlement, located to exploit a rise in elevation for defensive advantage. They are typically European and of the Bronze and Iron Ages. Some were used in the post-Roman period...

 http://www.geograph.org.uk/photo/222159, with a clearly visible earth and stone ditch and rampart http://www.geograph.org.uk/photo/369411 & http://www.geograph.org.uk/photo/609489.

The hill is approached by a couple of public footpaths across farmland from Crickhowell and Llanbedr

Llanbedr, Crickhowell

Llanbedr is a hamlet northeast of Crickhowell in the county of Powys in south Wales. It lies above the river known as the Grwyne Fechan just above its confluence with the Grwyne Fawr in the southern reaches of the Black Mountains range. The hamlet lies within the shadow of Table Mountain, an...

 and visited by the Beacons Way. It lies within an area designated as open country

Open Country

Open Country is a designation used for some UK access land.It was first defined under the 1949 National Parks Act , and was land over which an appropriate access agreement had been made...

 over which the public have the right to roam.

Geology

The hill is formed from Old Red Sandstone

Old Red Sandstone

The Old Red Sandstone is a British rock formation of considerable importance to early paleontology. For convenience the short version of the term, 'ORS' is often used in literature on the subject.-Sedimentology:...

 originating in the Devonian

Devonian

The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...

 period, specifically the sandstones of the Brownstones Formation, topped by rocks of the Quartz Conglomerate Group. The whole mass of rocks forming this outlier of Pen Cerrig-calch can readily be seen to dip more sharply to the south than nearby strata and is considered to be an excellent example of a translational slide

Landslide

A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...

.

External links

• Aerial photograph of Crug Hywel (Casglu'r Tlysau)