All 15 summits over 3,000 feet (914m) in Wales, linked in a single continuous effort: 50km of mountain terrain, 4,300m of ascent, starting in the Carneddau, crossing the Glyderau, and finishing on Yr Wyddfa — or vice versa — within 24 hours. One of Britain's great mountain challenges. This is Experience #90 of the Snowdonia 100, the last of the Challenges and Adventures category.
The Route
| Start | Pen y Pass (or Bethesda for south-to-north direction) |
| Classic direction | North to south: Carneddau → Glyderau → Snowdon |
| Summits | 15: all Welsh peaks over 914m (3,000ft) |
| Distance | Approximately 50km |
| Ascent | Approximately 4,300m |
| Time limit | 24 hours (conventional challenge time) |
The Summits
North to south: Foel Fras, Carnedd Gwenllian, Carnedd Llewelyn, Carnedd Dafydd, Pen yr Ole Wen (the Carneddau five) — then Glyder Fawr, Glyder Fach, Y Garn, Elidir Fawr, Tryfan (the Glyderau five) — then Crib Goch, Crib y Ddysgl, Yr Wyddfa, Y Lliwedd, and Moel Cynghorion (the Snowdon massif). The crossings between the massifs — descending from the Carneddau to the Ogwen Valley, then ascending Pen yr Ole Wen; descending from the Glyderau to Pen-y-Pass, then taking Crib Goch — are the crux time-management challenges.
Preparation
The Welsh 3,000s requires serious preparation: significant base fitness, map-reading ability across all terrain types including night navigation, experience of all the individual sections in normal conditions, and a support team at the road crossings. First-time attempts with an experienced guide or as part of an organised event are strongly recommended. The challenge has been completed by thousands of walkers and runners since it was formalized in the early 20th century — it is demanding but achievable for well-prepared parties.
Experience #90 of 100 — Challenges and Adventures category.
Independently written — Snowdon.com