Maescar includes the settlements of Sennybridge, Defynnog, Heol Senni and Pentre'r-felin, the last of which lies on the northern edge of the Geopark.

The lie of the land

The community ranges in height from around 180m beside the River Usk east of Sennybridge to 663m at Fan Nedd.  Other notable hills include:

• Fan Dringarth at 617m (SN 941193)
• Yr Allt at 604m (SN 905200)
• Cefn Llechid at 400m (SN 942275)
• Yr Allt at 354m (SN 914295)

The larger part of the area is drained by the Afon Senni which flows north into the River Usk.  The community also includes parts of the catchments of the south-flowing Afon Llia and Afon Dringarth.

Solid rocks

The southern part of the community is underlain by rocks of the Senni Beds and Brownstones Formations.  The northern part is underlain by those of the St Maughan's Formation.  All date from the Devonian period. 

The Senni Beds are well exposed at Craig Cwm-ddu and Blaen Senni where the overlying Brownstones Formation can also be seen in the steep hillside below Fan Nedd.

A large number of major geological faults run from SW to NE through the area, including the Swansea Valley and Cribarth Faults.

Legacy of the Ice Ages

Much of the lower ground is covered by glacial till.  There are also areas of hummocky sands and gravels in the Sennybridge area.  The valley bottoms are floored with alluvial deposits - sand, gravel and silt.  River terraces can be distinguished in the Usk valley.

The steep cliffs below Fan Nedd at Blaen Senni and again at Craig Cwm-du result from the presence of small glaciers at these locations.

Archaeology

The standing stone known as Maen Llia is located in the upper reaches of Cwm Llia.  The Iron Age hillfort of Y Gaer lies 1 mile south of Defynnog.  The Roman road known as Sarn Helen runs through the southeast of the area.  The remains of Castell-du can be found in Sennybridge.

Maps

Geology

Sheets 213 ‘Brecon’ & 231 ‘Merthyr Tydfil’ of the British Geological Survey’s 1:50,000 map series of England and Wales give full coverage between them of both the bedrock geology and superficial deposits of the Community.  Sheet 231 is available in two editions.  BGS publish a 'memoir' and a 'sheet explanation' to accompany these maps.

General

The following Ordnance Survey maps cover the Community:

• Landranger sheet 160 'Brecon Beacons' (1:50,000 scale)
• Explorer sheet OL12 'Brecon Beacons National Park/Western area' (1:25,000 scale)

Public transport

Bus services operate along the A40 between Llandovery and Brecon. The nearest railway station is at Llandovery.

See Traveline Cymru for bus and train services including stops, timetables and route-planning information.