Lôn Las Ogwen

Overview

About Lôn Las Ogwen

Why go

Old railway and slate heritage throughout
Builds from shady woodland to a dramatic glacial valley

Heads up

Long one-way day with return logistics
Shared paths and several busy-road crossings

Much of the line follows the old railway that carried slate from Bethesda quarry down to the coast, so the industrial story is legible the whole way: inclines, tips, sheds and the bones of a working landscape. The scenery builds rather than repeats, from enclosed riverside woodland to the wide upper trough with the Carneddau on one side and the Glyderau on the other. In the top section the glacial geology is unusually easy to read, with a U-shaped trough, aretes, truncated spurs, hanging valleys and rock steps in plain view.

Parkwolf’s verdictWhy it is worth doing

Map & elevation

The route

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Full map

Elevation7–299 m

TrailheadPort Penrhyn at the white Old Port Office53.23164, -4.11005

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Plan your hike

Before you go

Parking

Start at Port Penrhyn, just outside Bangor. Take the turning to the port before the sharp bend on the A5, keep to the left fork, and use the parking behind the white Old Port Office at the trail start.

Best time to go

Spring is the pick for the lower half, when bluebells and wood anemones come out in the woodland and bird song is at its strongest. Otters have re-established themselves in the Cegin Valley and mountain ponies are sometimes about in the upper valley, though neither is a sighting you can count on. For photography, walk south from Port Penrhyn in the morning and save the upper Nant Ffrancon for later light, when low sun rakes across the slate and picks out the ridgelines and hanging valleys.

Safety

Take particular care on the short road sections, the A4244 bridge and the Penrhyn Quarry access-road crossing; the final climb to Ogwen Cottage is steep. Keep dogs close around livestock and wildlife.

A park ranger sits on a dash-mounted phone, talking, as Parkwolf’s Tour Guide plays “Army Cutworm Moths: A Grizzly Bear Buffet” on Grand Loop Road below Dunraven Pass in Yellowstone — Parkwolf Tour GuideThe highest, rockiest slopes around here are a summer buffet for grizzly bears.

Eryri Tour Guide

Your drive to Lôn Las Ogwen, narrated.

Parkwolf is a GPS audio tour guide for Eryri National Park. As you drive, it chimes in with what’s ahead: hidden gems, upcoming stops, history, geology, and wildlife, right through your car’s speakers.

Hiking Lôn Las Ogwen

Route type and distanceThis is a one-way multi-use route of about 18 km (11 miles) from Port Penrhyn, just outside…

This is a one-way multi-use route of about 18 km (11 miles) from Port Penrhyn, just outside Bangor, to Ogwen Cottage/Idwal Cottage at the head of the Nant Ffrancon valley. It forms National Cycle Network Route 82 and is open to walkers, cyclists, runners, dog walkers and, where permitted, horse riders. All distances and times here are for the full route in one direction, not there and back. Allow roughly 5 to 5.5 hours on foot for the whole line; cycling it is considerably quicker.

How the route unfoldsStart behind the white Old Port Office at Port Penrhyn.

Start behind the white Old Port Office at Port Penrhyn. The path runs through woodland beside a meadow and the Penrhyn Estate walls, passes close to the A5 and into the Cegin Valley, following the river over bridges and under the A55. Beyond Tregarth it goes through the new tunnel and joins the River Ogwen, passing Coed y Parc and the old Felin Fawr slate works, then climbs gently between slate tips to Ogwen Bank. From there the corridor opens into the glaciated Nant Ffrancon valley, past slate waste and the old road known locally as the Roman Road, before a final steep pull to Ogwen Cottage/Idwal Cottage and the visitor centre and snack bar area.

Difficulty, surfaces and sharing the pathThe project describes the cycleway as suitable for riders of all abilities, and the gradients…

The project describes the cycleway as suitable for riders of all abilities, and the gradients are mostly gentle valley-floor or railway grades, but a full walk is still a long day because of the length, the one-way logistics and the final punishing climb toward Ogwen Cottage. Surfaces mix paved asphalt with gravel, plus short road sections. Expect to share the corridor with cyclists, runners, dog walkers and occasional riders, so keep left where sightlines are poor and pass wide.

Roads and crossingsThere is a short road section under the A55, a bridge over the busy A4244, and a crossing of…

There is a short road section under the A55, a bridge over the busy A4244, and a crossing of the Penrhyn Quarry/Zip World access road near Ogwen Bank that needs care and patience, especially with children or a bike trailer. Traffic near the A5 turning at the Port Penrhyn end also deserves attention.

Access, parking and getting backThe stored route starts at Port Penrhyn.

The stored route starts at Port Penrhyn. Take the turning to the port before the sharp bend on the A5, keep to the left fork, and use the parking behind the white Old Port Office at the trail start. Because the route does not return to its start, plan the finish before you set out: either retrace your steps or arrange transport from the upper end. For a shorter and more concentrated version, join at one of the middle access points and walk or ride only the upper valley section, which carries most of the drama. Refreshments on the route are limited to the farm shop and cafe at Moel y Ci and the visitor centre and snack bar area at the top.

DogsDogs are welcome on the public footpaths and open-access land along the way, under close…

Dogs are welcome on the public footpaths and open-access land along the way, under close control at all times. Use a short lead near livestock or wildlife, and on open-access land keep dogs on a lead no longer than 2 m between 1 March and 31 July. There is no blanket right to let a dog run free here, and the shared-use surface makes a lead sensible around cyclists in any case.