Cwm Idwal Walk: Distance, Time, Ogwen Parking & Bus

Cwm Idwal at a glance

5 kmcircular

140 mascent

2 hrsEryri estimate

Popularhow busy (Eryri)

A circular walk in a glacial valley, Wales' first National Nature Reserve. Eryri's route climbs steeply towards Twll Du (Devil's Kitchen) over loose rock and boulders; a shorter path round the lake avoids that climb and can suit less experienced walkers.

Start: Canolfan Ogwen Centre, Nant Ffrancon (SH 649 603)
Grade: Moderate (Eryri)
Map: OS Explorer OL17
Official route: Eryri route page, PDF and GPX

100 m200 m300 m400 mStart of the mapped circuitBack to the start

Shape of the walk round the circuit. Approximate heights along the OpenStreetMap route line, from Copernicus GLO-90 terrain data (via Open-Meteo); the 90 m grid smooths the highest point. Distances and ascent figures on this page are Eryri's.

Canolfan Ogwen Nant Ffrancon
Llyn Idwal Glacial valley, a National Nature Reserve
Towards Twll Du Eryri's route: steep, loose rock and boulders. Or take the shorter path round the lake.
Back to Ogwen Circular, about 2 hours

Key points along the way, in order, from Eryri's route description. Not a substitute for a map.

ModerateEryri gradeCwm Idwal
Hard/StrenuousEryri grade
Scramblehands needed (National Trust)

Eryri grades Cwm Idwal Moderate. Its route climbs steeply towards Twll Du; the shorter path round the lake avoids that climb.

The Cwm Idwal circuit round Llyn Idwal, as mapped in OpenStreetMap. Sketch only, not for navigation. Route lines © OpenStreetMap contributors.

Plan your Cwm Idwal day

Your pace

1. Pick a day

Loading the live forecast…

Sunrise

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Sunset

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Daylight

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Latest safe start

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Best day this week

Our own guide, not an official rating: a weather score from the same rules of thumb as the warnings (gusts, rain, cloud, wind chill, freezing level), lowered on days that are usually busy. Busyness uses Eryri's 2025 walker counts by weekday and month, so it shows a typical pattern, not a crowd forecast. Tap a day to see it.

Sunrise hike: what time to start

Reach the top

Start walking by

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You will walk up in the dark: carry a head torch with spare batteries, and a second light. Eryri advises carrying a torch and whistle in case you are caught on a summit after dark.
It is much colder before dawn and at the top: pack extra warm layers.
Navigation is harder in the dark: know the path, and carry a map and compass and the skills to use them.
Early buses may not run yet: check the first bus time, or the parking rules, before you plan the start.
Go with others, tell someone your plan, and turn back if the weather is poor.

Hour-by-hour forecast: Cwm Idwal

Wind and gusts in mph. Freezing level in metres above sea level. Forecast data: Open-Meteo.

Before you go, also check the Met Office mountain forecast, MWIS.

2. Getting there

Map

The route map (OpenStreetMap) loads when you scroll here.

How busy it gets

Pages you have opened, and the last forecast, are kept on this device, so the plan still opens with no signal.

Monthly walker counts, 2025

One-way counts from Eryri's Idwal counter in Eryri's Visitor Monitoring Report 2025; total 131,434.

Stay safe

Ask the AdventureSmart three questions: do I have the knowledge and skills, do I know what the weather will be like, and am I confident I have the right gear?
In an emergency, dial 999 or 112, ask for the Police, then Mountain Rescue.
Register your phone for emergency texts before you go: text register to 999.
Do not walk on the Snowdon Mountain Railway track. Keep dogs on leads near livestock.
Turn back if the weather turns or you are behind time. The summit will still be there.

Full kit list and safety guide

Other Eryri walks

Distance km

Minffordd Path9 km
Pony Path (Tŷ Nant)10 km
Cwm Idwal5 km

Ascent metres

Minffordd Path788 m
Pony Path (Tŷ Nant)727 m
Cwm Idwal140 m

Time hours (Eryri)

Minffordd Path6 hrs
Pony Path (Tŷ Nant)5 hrs
Cwm Idwal2 hrs

Distance (there and back, or round the circuit), ascent and Eryri's time for each walk. Tryfan is left out: no distance or time is published, because every way up is a scramble.

Frequently asked questions

How long is the Cwm Idwal?

5 km (circular), with an estimated 2 hours walking, according to Eryri National Park Authority.

How much ascent is on the Cwm Idwal?

140 metres, according to Eryri.

How hard is the Cwm Idwal?

Eryri grades it Moderate. It suits people with some countryside walking experience and reasonable fitness; walking boots and waterproofs are essential.

Where does the Cwm Idwal start?

Canolfan Ogwen Centre, Nant Ffrancon (SH 649 603).

Where do I park for the Cwm Idwal?

Ogwen car park (Eryri): £8 a day (until 22:00) · £5 up to 4 hrs. Bethesda Football Club (park and bus): £6 a day (pay and display).

Is there a bus to the Cwm Idwal?

T10 bus (Bangor – Corwen): stop "Llyn Ogwen", a minute's walk from the start. Bws Ogwen: 9-seat electric bus from Bethesda to Llyn Ogwen.

Is there an easier walk at Cwm Idwal?

Yes. Eryri says a shorter path around the lake avoids the steep climb towards Twll Du (Devil's Kitchen) and can suit less experienced walkers.

Sources

Every figure on this page was checked against these sources on 20 October 2026.

Cwm Idwal: distance, time, parking and bus