| Pen Allt-mawr | |
|---|---|
 Pen Allt-mawr from Pen Cerrig-calch | |
| Highest point | |
| Elevation | 719 m (2,359 ft) |
| Prominence | 103 m (338 ft) |
| Parent peak | Waun Fach |
| Listing | Hewitt, Nuttall, HuMP |
| Coordinates | 51°54′42″N 3°09′16″W / 51.9118°N 3.1544°W |
| Naming | |
| English translation | top of the big slope |
| Language of name | Welsh |
| Geography | |
 | |
| Location | Black Mountains, South Wales |
| OS grid | SO206243 |
| Topo map | OS Landranger 161 |
| Name | Grid ref | Height | Status |
|---|---|---|---|
| Pen Twyn Glas | SN969193 | 646 metres (2,119 ft) | sub Hewitt, Nuttall |
Pen Allt-mawr is a 719 metres (2,359 ft) high subsidiary summit of Waun Fach and the third highest peak in the Black Mountains in south-eastern Wales. A very recognisable and prominent peak of the Black Mountains, it lies near the end of the more westerly of Waun Fach's two broad southern ridges. Its top Pen Twyn Glas is to the north, while its close neighbour Pen Cerrig-calch is to the south.[1] A prominent spur 1 km to the SSW of the summit is known as Pen Gloch-y-pibwr. The stepped Bryniog ridge curves southward from this point.
Its summit is stony and has damaged Bronze Age cairns and a large shelter cairn together with a trig point.[2] Further Bronze Age cairns are found along the western edge of the plateau to the south.
- ^ Nuttall, John & Anne (1999). The Mountains of England & Wales - Volume 1: Wales (2nd edition ed.). Milnthorpe, Cumbria: Cicerone. ISBN 1-85284-304-7.
- ^ "Pen Alltmawr Cairn II (502375)". Coflein. RCAHMW. Retrieved 17 May 2020.