Trum y Ddysgl
3 classifications here — Marilyn, HuMP and Simm — belong to lists OpenFell holds only part of, so they have no list page. See how far the coverage goes.
- Height
- 709.7 m · 2,328 ft
- Prominence
- 208.6 m
- Grid reference
- SH 54487 51646
- Coordinates
- 53.04221, -4.17197
- County / area
- Gwynedd
- Region
- Snowdonia
- OS Landranger
- 115
- OS Explorer
- OL17W 254
- Summit feature
- no feature: grass
- Key col
- SH 5309 5072 (501.1 m)
About Trum y Ddysgl
Trum y Ddysgl is the second highest summit on the Nantlle Ridge and one of the ridge's two Marilyns, the other being Craig Cwm Silyn. Its shape is the draw: two arêtes, dark glacial cwms and rocky ground throughout.
Three further tops belong to the peak, and together they make up a rocky, relatively narrow stretch of the Nantlle ridge. Mynydd Mawr, Yr Wyddfa and Moel Hebog are all close at hand in the view.
Background written from facts in the Wikipedia article on Trum y Ddysgl (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
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- Daylight
- —
- Civil twilight ends
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Computed astronomically for 53.042, -4.172. Plan your finish with the daylight safety planner.
Summit weather live
Loading forecast for the summit (710 m)…
Forecast adjusted to summit altitude. Weather data from MET Norway (CC BY 4.0).
Long-distance paths past this hill
One waymarked long-distance route runs 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 |
|---|---|---|
| Snowdonia Slate Trail | 135 km | 1.8 km |
Route lines © OpenStreetMap contributors (ODbL); distance from the summit computed by OpenFell.
The Trum y Ddysgl group
3 other listed summits sit in the same prominence group, with Trum y Ddysgl as the independent hill at its head.
| Summit | Height | Drop |
|---|---|---|
| Mynydd Drws-y-coed | 695 m | 58 m |
| Mynydd Tal-y-mignedd | 653 m | 52 m |
| Y Garn | 633 m | 21 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.
Nearest listed peaks
| Peak | Height | Distance |
|---|---|---|
| Mynydd Drws-y-coed | 695 m | 0.4 km |
| Mynydd Tal-y-mignedd | 653 m | 1 km |
| Y Garn | 633 m | 1.2 km |
| Craig Cwm Silyn | 734 m | 2.4 km |
| Mynydd Mawr | 698 m | 3.1 km |
| Moel Lefn | 638 m | 3.2 km |