The Best Hikes in Eryri National Park

To fully appreciate the beauty of Eryri (Snowdonia), you need to know a little about how the land was formed. The geology here is complex, but we can summarise the story to give a basic understanding that you can take into hills.

The Welsh Basin

About 495 million years ago, Wales occupied a shallow sea known as the Welsh Basin. The Basin lay between two areas of Avalonia, a land which contained south Britain and parts of Ireland. Sedimentary rocks were laid down within this shallow sea and formed the basement rocks of the region.

Across the ancient Iapetus Ocean was another continent, Laurentia, which contained Scotland. Tectonic movements caused the two land masses to start moving towards each other. As the Iapetus Ocean closed, the heavier land masses caused the seabed to dive below it. The process, called subduction, caused the crust to melt and erupt at the surface as volcanoes.

A Time of Fire and Ice

This is what happened for about 100 million years, with substantial explosive volcanoes forming an island arc in the Welsh Basin. These processes formed the Glyderau, Carneddau, and Yr Wyddfa (Snowdon). Four hundred million years ago, the two land masses finally collided, joining Scotland to England. The force of this collision caused the sea sediments and volcanic rock to ruck up into huge fold mountains.

The action of water and, more recently, ice have reduced these mighty mountains, once higher than the Alps, to the hills we see today. The action of the various glacial periods can be seen everywhere in the park, from the high glacial cwms to the classic u-shaped valleys to the hauntingly beautiful glacial lakes.

A Volcanic Landscape

These fantastic processes have created an absolute wonder of nature that you could spend a lifetime exploring. There is some of the best rock climbing in the world in this area, as the hard volcanic rock eroded by ice has created some fantastic routes for every level. The walking is superb, from tricky scrambles up ice-carved arêtes to rambles through lovely valleys and forests. If water is your thing, wild swimming is very popular here, with folk seeking out high glacial lakes like Llyn Idwal or Llyn Bochlwyd.

Snowdon is derived from the old English’ Snaw Dun’, meaning snow hill. The Welsh name Yr Wyddfa means ‘burial mound’. Legend tells that this is the burial place of the giant Rhita Gawr, killed in battle with King Arthur. The Welsh telling is a lot more evocative than Snow Hill!

Rightful Names Restored

The park authority used the English name Snowdonia when referring to the national park with the Welsh name alongside for many years. However, following a long campaign by different groups, the decision was made in February 2023 to primarily use the Welsh names. So, the national park will now be known by its Welsh name, Eryri, and Snowdon as Yr Wyddfa.

To the Summit and Beyond

At 3,560 ft/1,085 m, Yr Wyddfa is the highest ground in the UK south of Scotland. For that reason alone, it is very popular. Some 600,000 people climb this hill yearly, and the summit can get very busy in the summer. Additionally, there is a mountain railway and a café at the top – the summit can resemble a festival on some days!

The famous Crib Goch (red comb, pictured) is a glacial arête, a popular route to the summit for experienced hill walkers with scrambling skills and a good head for heights. Below is the more accessible Pyg Track, which starts at Pen y Pass.

Nevertheless, it is a fantastic mountain, and there are some quiet routes to the summit for those willing to be a little more adventurous. I am a big fan of the Watkin path, which starts at the lowest point in Nantgwynant. The route passes through the old quarries and mines, rising up steep slopes to reach Bwlch Ciliau on the famous Snowdon Horseshoe. From here, a little route-finding is necessary until you reach the end of the ridge at Bwlch Main. It’s a short pull to join the crowds on the summit now. To return, you can take the same route. However, if you have transport back to your start point, a better return route is the Rhyd-Ddu path to the village of Rhyd-Ddu and a well-earned pint at the Cwellyn Arms.

On the other side of the Pass of Llanberis is the Glyderau. Glyder is derived from the Welsh cludair, meaning “heaps of stone”. This is an apt name for this range, as frost–shattered rock covers the tops. At the summit, the atmospheric Castell y Gwynt (castle of the wind) looks very spooky when you come across it in the mist!

A famous cantilever stone on Glyder Fach is pictured. Many have tried to move it by jumping up and down to no avail. The rock formations are typical of what you will see on the summits of both Glyder Fach and Fawr.

The action of frost and ice on the Glyders has made for some excellent mountain entertainment with easy scrambling routes up Y Gribin and Seniors Ridge. There is a popular scrambling route up the whale back north ridge of Tryfan, but only for experienced hillgoers. Sadly, it attracts folk ill-prepared for the difficulties, and it is the accident black spot of the park.

The Route from Idwal Cottage

There is an easy and popular route from Idwal Cottage past the stunning Llyn Idwal to the foot of Twll Du (the Devil’s Kitchen), a cleft in the sheer rock face. Mist swirls around these cliffs, and on some days, the mist rises up through the cleft, and it’s easy to imagine the Devil knocking up a brew at the foot of the cliff.

You can carry on around the lake to return to Idwal Cottage and marvel at the rock climbers above you on the Idwal slabs. One of the outdoor magazines held a poll, and this part of Eryri (Snowdonia) was voted the best square mile of mountain in Britain; it’s easy to see why.

A Steep Climb from Llyn Idwal

One of my favourite days out is to climb the northeast ridge of Y Garn from Llyn Idwal. The path is steep but well-defined and maintained. As you climb higher, you look down into Cwm Clyd. On a good day, you get exhilarating views across the Menai Straight to Ynys Môn (Anglesey). From the summit, head south to Llyn y Cwn below the steep slopes of Glyder Fawer, then take the prominent path northeast down steep boulders and end up below the Devil’s Kitchen. Take care here, as the path may be well-marked but sometimes requires both hands.

Across the Ogwen Valley from the Glyderau is the upland area known as the Carneddau. This massif is the largest area of continuous land above 3000 ft/914 m in England and Wales, with seven peaks over 3000 ft/914 m. Carneddau translates to ‘cairns’, and the extensive area covers nearly 200 sq km/77 sq miles, roughly 10% of the national park. It is also remote; you can walk from the Ogwen Valley northwards to the coast at Conwy without crossing a road.

Steve Recommends…

I love it here! The hills are more rounded than the rocky peaks of the Glyderau, but they contain steep-sided lonely valleys such as Cwm Eigiau or Cwm Llugwy. The crags make for fine climbing and scrambling, while the rounded tops make for brilliant hill walking.

It’s quiet here too. On a good day, parked cars line the A5 road through the Ogwen Valley, with most of those folk heading up Tryfan or Cwm Idwal. Meanwhile, the smart money heads up Cwm Lloer for peace and solitude.

A Great Day Walk in Eryri (Snowdonia)

Alternatively, a great day walk starts on the A5 in the Ogwen Valley, just west of Gof Uchaf. Take the footpath past Tal y Llyn Ogwen and up the valley following the pretty Afon lloer. Just before the mountain lake, Ffynnon Lloer, take the obvious path west towards the crags of Pen yr Ole Wen. Clamber up the small rake in the crags (take care here), then follow the ridge to the hill’s summit. Follow the ridge line above Cwm Lloer to Carnedd Dafydd. Carnedd Dafydd and Llewelyn are named after medieval Welsh princes.

From here, head east above the steep slopes of Ysgolion Duon to the clear ridge of Bwlch Cyfryw-drum. You can carry onto Carnedd Llewelyn here, returning the same way to the Bwlch. The route down is by taking the grassy slopes, initially south following the broad ridge, then turning west below Creigiau Malwod to Bryn Mawr and then following Afon Lloer back to the A5.