Mynydd Du
About Mynydd Du
Mynydd Du, also known as the Black Mountain, is the remote western section of the Brecon Beacons. The high plateau of Bannau Sir Gaer includes the striking glacial lakes of Llyn y Fan Fach and Llyn y Fan Fawr.
Height & Prominence of Mynydd Du
Mynydd Du stands at 802 metres (2631 feet) above sea level, according to Ordnance Survey data. Its topographic prominence is 542 metres, meaning it rises at least that far above the col connecting it to the nearest higher peak. Mynydd Du is part of the Brecon Beacons. The OS grid reference is SN 825218, which you can use to locate the summit on any Ordnance Survey Explorer or Landranger map.
Mynydd Du carries the classifications of Hewitt, Nuttall, Marilyn.
Location & Nearest Towns
Mynydd Du is located in Wales, Carmarthenshire, within Brecon Beacons National Park. It sits in the Black Mountain area. The nearest towns and villages include Llanddeusant, Llyn y Fan Fach, Llyn y Fan Fawr, and others, where you can find accommodation, pubs, and supplies before or after your walk.
For official access information and any seasonal restrictions, check the Brecon Beacons National Park authority.
Interesting Facts
- The lakes Llyn y Fan Fach and Llyn y Fan Fawr sit below dramatic escarpment cliffs
- Associated with the Welsh legend of the Lady of the Lake
- Much quieter than the central Brecon Beacons
- Part of the Brecon Beacons National Park
Safety Tips
Always check forecasts before setting out. Summit conditions differ dramatically from valley level.
Carry map, compass/GPS, water, food, first aid, whistle, torch, and waterproofs.
Tell someone your route and return time. Stick to marked paths. Be ready to turn back.
Ask for Police, then Mountain Rescue. Know your grid reference.
On the Mountain: Walking Mynydd Du
Mynydd Du is a moderate walk that rewards careful planning. The summit sits at 802m, where conditions can feel distinctly different from the valley — wind speeds are typically 30–50% stronger above 800m, and the temperature drops roughly 1°C for every 100m of ascent. In cloud, the cairn at the top can be hard to spot, so keep a map and compass to hand even on well-marked paths.
After your walk, the nearest village — Llanddeusant — is a good place for a pint and a debrief. For detailed route descriptions and trip reports from other walkers, Walkhighlands is an excellent resource.
Nearby Dining
- Llanddeusant village
- Brecon town
Frequently Asked Questions
Is Mynydd Du one of the best mountains to climb in the UK?
Yes, Mynydd Du is considered one of the best mountains to climb in the UK thanks to its scenic routes, 802m elevation, and moderate difficulty level.
What difficulty level is Mynydd Du?
Mynydd Du has a difficulty rating of Moderate. Various routes are available for different experience levels.
When is the best time to climb Mynydd Du?
The best season is Spring to Autumn. Summit temperatures are typically 5–10°C colder than the valley, and conditions can change rapidly.
Why Visit Mynydd Du?
Mynydd Du stands at 802m (2631ft) in Wales, Carmarthenshire. Classified as a Hewitt and Nuttall and Marilyn, it is a rewarding destination for hikers, climbers, and photographers.
Browse our UK mountains directory to discover more peaks, or see all mountains A–Z.
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