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- Height
- 871.5 m · 2,859 ft
- Prominence
- 28.2 m
- Grid reference
- SO 00720 21335
- Coordinates
- 51.88167, -3.44381
- County / area
- Powys
- Region
- Llandovery to Monmouth
- OS Landranger
- 160
- OS Explorer
- OL12E
- Summit feature
- large cairn
- Key col
- SO 0091 2139 (843.3 m)
About Corn Du
Corn Du is the lower of the twin tops shared with Pen y Fan, standing about 550 metres to its south-west and just 13 metres beneath it. At 871.5 metres it is the second highest peak in South Wales, within Bannau Brycheiniog (Brecon Beacons National Park).
A well-built Bronze Age cairn with a central burial cist marks the summit, matching the one on Pen y Fan. Both tops rise far enough above the surrounding moorland to be recognised from a long way off. The views are wide: the Black Mountain and Fforest Fawr stand out westward, Mynydd Epynt lies north beyond Brecon, and further stretches of the escarpment run east.
Background written from facts in the Wikipedia article on Corn Du (CC BY-SA 4.0). Heights, prominence and grid references come from the Database of British & Irish Hills, not from Wikipedia.
Access rights here
Conditional Right to roam: Right to roam only on mapped CRoW open access land.
Permission needed Wild camping: Permission needed everywhere.
General position for Wales — local byelaws, seasonal restrictions and closures can override it. Full details: access rights in Wales · check another location.
Daylight at this summit today
- Sunrise
- —
- Sunset
- —
- Daylight
- —
- Civil twilight ends
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Computed astronomically for 51.882, -3.444. Plan your finish with the daylight safety planner.
Summit weather live
Loading forecast for the summit (872 m)…
Forecast adjusted to summit altitude. Weather data from MET Norway (CC BY 4.0).
Long-distance paths past this hill
3 waymarked long-distance routes run within 2.5 km of the summit — useful if you are linking this hill into a longer walk, or want a made path for the approach.
| Route | Total length | From summit |
|---|---|---|
| Cambrian Way | 483 km | over the top |
| Beacons Way | 155 km | over the top |
| Taff Trail | 101 km | 2.4 km |
Route lines © OpenStreetMap contributors (ODbL); distance from the summit computed by OpenFell.
Which hill this one belongs to
Corn Du is not counted as an independent hill in its own right. In prominence terms it belongs to Pen y Fan (886 m) — the nearest Marilyn you can reach from this summit without first dropping below its key col, 843 m.
Grouping is by prominence alone: a summit belongs to the nearest higher Marilyn it connects to without a deeper intervening col. Over a large massif that can gather hills no one would walk in a single day, and which few would describe as parts of the same mountain — it is a measure of independence, not a suggested route.