Glan Dena via Cwm Lloer up Pen yr Ole Wen: route map, distance and time

A path into Cwm Lloer, then up the east ridge to the summit.

Glan Dena via Cwm Lloer starts at about 314 m and gains 631 m over 2.8 km to 949 m on the track. It is steep from the start: the first kilometre climbs 169 m (17%). The steepest kilometre is the one ending at 2.8 km, which climbs 216 m at an average of 27%. That last pull ends at the summit. About 61% of the way is steeper than 1 in 5, so expect hands-on-knees going and a slow descent.

Glan Dena via Cwm Lloer at a glance

Glan Dena via Cwm Lloer map

The track from the start (green) to the summit (blue), with a marker at each kilometre.

Height profile and getting to the start

Download the Glan Dena via Cwm Lloer GPX

Ascent only: plan your way down. A planning track, not checked on the ground; it doesn't show safe scrambling moves. Track data © OpenStreetMap contributors (ODbL), heights from a terrain model.

Glan Dena via Cwm Lloer kilometre by kilometre

Height, climb and average gradient for each kilometre of the track, with a grid reference at the end of each one to check your position on the map.

How long Glan Dena via Cwm Lloer takes

Times leave out stops. Coming down the same way, the table counts the ascent once; steep descents on rough ground can be as slow as the climb.

• Today: sunrise 07:48, sunset 18:14. Start by 14:59 to be down before dark, allowing 2h 15m for the walk and an hour for stops.
• Tomorrow: sunrise 07:49, sunset 18:12. Start by 14:57 to be down before dark, allowing 2h 15m for the walk and an hour for stops.

Pen yr Ole Wen summit weather for this route

• Marginal Today Sunday 18 October

  Overcast, up to 4°C at the summit, feeling as cold as -4°C, summit wind 25 mph gusting 31 mph, 21% chance of rain. Rated Marginal. Sunrise 07:48, sunset 18:14.

• Marginal Tomorrow Monday 19 October

  Dense drizzle, up to 5°C at the summit, feeling as cold as -3°C, summit wind 35 mph gusting 44 mph, 73% chance of rain. Rated Marginal. Sunrise 07:49, sunset 18:12.

Best day of the next seven for Glan Dena via Cwm Lloer: Sunday 18 October, with summit gusts around 31 mph and a 21% chance of rain.

Cloud inversion tomorrow morning: 1% (Low), best around 05:00. 7-day inversion outlook.

Hour-by-hour Pen yr Ole Wen forecast · 14-day forecast · Is it safe to climb Pen yr Ole Wen?

Before you go, also check: MWIS Snowdonia forecast · Met Office mountain forecast.

What to take today

• An insulated jacket, hat and warm gloves: it feels like -4°C on top.
• A waterproof jacket. It can rain on the tops in any forecast.
• A windproof layer, and poles for balance in gusts to 31 mph.
• Microspikes for icy paths. In snow, an ice axe and crampons and the skills to use them.
• Map and compass, and the skills to use them. A phone is a backup, not a plan.
• A head torch, food, water, a charged phone and a small first aid kit.

About Pen yr Ole Wen

Pen yr Ole Wen is the steep-sided Carneddau summit above Llyn Ogwen, one of the Welsh 3000s and the first step onto the Carneddau ridge. More about Pen yr Ole Wen, with the live forecast.

On the lists: Furth, Hewitt, Nuttall.

Extend the walk: tops near the summit

• Carnedd Dafydd (1,044 m), 1.3 km north-east
• Foel Meirch (799 m), 1.8 km north
• Tryfan (918 m), 2.7 km south
• Foel-goch (831 m), 2.8 km west

Challenges that include Pen yr Ole Wen

• Welsh 3000s · 15
• Welsh 100 Challenge · 100
• Snowdonia 900m Peaks · 16
• Carneddau Traverse · 7
• Paddy Buckley Round · 47
• Furths · 34
• Hewitts · 523
• Nuttalls · 442

More walks from Glan Denau path junction

Routes in Peakify's guides that start within 500 m of this one, for another day from the same car park.

• Ogwen via Cwm Lloer and Pen yr Ole Wen up Carnedd Dafydd
• Ogwen via Pen yr Helgi Du up Carnedd Llewelyn
• Ogwen via Carnedd Dafydd up Carnedd Llewelyn
• East Ridge via Ffynnon Lloer and Carneddau ridge up Carnedd Llewelyn
• Heather Terrace and South Ridge up Tryfan
• South Ridge up Tryfan

Other routes up Pen yr Ole Wen

In an emergency

Call 999, ask for the police and then mountain rescue. Give your location (the start is at SH 669 607, the summit at SH 655 619), what happened and how many are in your group. If you have no signal for a call, a text to 999 works once you have registered your phone with emergencySMS: text "register" to 999 before you go.

Glan Dena via Cwm Lloer: questions and answers

How far is Glan Dena via Cwm Lloer?

Glan Dena via Cwm Lloer is 2.8 km one way to the summit of Pen yr Ole Wen, with 660 m of ascent. There and back by the same way is about 5.6 km.

How long does Glan Dena via Cwm Lloer take?

About 1h 40m to the summit of Pen yr Ole Wen and 2h 15m there and back by Naismith's rule (5 km/h plus 10 minutes per 100 m of ascent), before stops. A relaxed group takes nearer 2h 45m for the round trip.

How steep is Glan Dena via Cwm Lloer?

The steepest 500 m averages about 30%, starting 2.2 km from the start, and 61% of the way is steeper than 1 in 5. Glan Dena via Cwm Lloer climbs 631 m in all on the track.

Where do you park for Glan Dena via Cwm Lloer?

Glan Dena via Cwm Lloer starts from Glan Denau path junction. The grid reference is SH 669 607. No checked car park for this start; find lawful parking nearby

Is Glan Dena via Cwm Lloer suitable for beginners?

Yes, for fit walkers on a clear day. Peakify grades it Moderate: a long climb on a made path, but the top is high, exposed and colder than the start. Turn back if the cloud comes down and you can't navigate.

What time should I start Glan Dena via Cwm Lloer today?

By 14:59 at the latest. Sunset on Pen yr Ole Wen today is 18:14, Glan Dena via Cwm Lloer takes about 2h 15m there and back, and that leaves an hour for stops. Start earlier in winter or if the forecast turns.

Is there a GPX for Glan Dena via Cwm Lloer?

Yes. Download it from this page. It is an ascent-only planning track from the start to the summit, plotted on OpenStreetMap paths and not checked on the ground.