Overview
Explore Cwm Idwal's ice-sculpted beauty and dramatic mountainous scenery, rich in geological and scientific history
Nestled within the rugged embrace of northern Snowdonia, lies a place of unparalleled natural beauty and scientific intrigue. Located 10 miles southwest of Bangor, Cwm Idwal offers a sanctuary of serenity and splendour, waiting to be explored. Here, the landscape tells a story of ancient volcanic activity and the relentless land-shaping force of ice, over millennia. Towering rock pinnacles, etched by the hands of time, stand sentinel over the pristine waters of Llyn Idwal, which casts reflections of the surrounding peaks like a shimmering mirror. Recognized for its exceptional geological and botanical significance, Cwm Idwal was bestowed the honour of being the first Welsh National Nature Reserve in 1954.
Your journey begins with a gentle ascent through the picturesque Ogwen Valley, gradually leading you to the foot of the majestic Glyderau mountain range. As you embark on the circular walk around Llyn Idwal, prepare to be mesmerized by the tranquil beauty of this glacial lake, cradled within the amphitheatre-like basin of the cwm. But here you'll find more than just a scenic gem, it is a sanctuary teeming with life, home to a rich tapestry of plant and animal species, some of which are rare or endangered.
Steeped in history and scientific exploration, this timeless landscape has captivated the minds of renowned figures like Charles Darwin, who meticulously studied its geology to further our understanding of the natural world. Now, it beckons you to follow in their footsteps, embarking on your own personal odyssey of discovery amidst the wonders of this ancient land. So lace up your boots, embrace the call of adventure, and immerse yourself in the breathtaking beauty of one of Eryri's most spectacular treasures.
Go prepared, stay safe, and enjoy the hike!
key info
duration: 1.5 - 2.5 hours
length: 3 miles
type: Circular
total ascent: 318m
difficulty:
our rating:
Crowd levels: high
signage: low
toilets: Start
parking
The hike starts at the Ogwen Centre pay and display car park near the National Trust's Ogwen Cottage (the postcode is LL57 3LZ, but please note that this doesn't take you directly to it so it's best to use the Google map directions above). The car park is quite small and fills up quickly, so either arrive early or be prepared to wait a while for a parking space (I've had to wait for up to 20 minutes). I think the car park is open 24 hours a day, every day of the year, but all tickets expire at midnight, so you'd have to be back by then to buy another one for the next day. It costs £3 for 4 hours, or £6 for the whole day. The price is correct at the time of writing (February 2024). The Pay and Display machine only takes cards or contactless, and cash is not accepted. The mobile signal at the car park can be quite bad, so if you're using a navigation app you're best downloading the route before you arrive (or download the PDF guide from this page). If the car park is full and you don't want to wait, please see the below section for more options.
Alternative parking
3 minute walk to start of hike*
10 minute walk to start of hike**
*This is a free layby off the A5, with space for around 9 cars. It is just as likely as the main car park to be full, but if you pass it on your way to the main car park and there's a space, take it! If you do park here, you need to walk to your right (when the layby is behind you) until you reach Ogwen cottage near the start point.
**This is a free car park of the A5, with space for around 50 cars. Again, as with the above, this car park is just as likely as the main one to be full, so if you see a space, take it. If you do park here, you need to walk to your rileft (when the car park is behind you) until you reach Ogwen cottage near the start point.
route map
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route GUIDE
NOTE: When hiking I use the Ordnance Survey phone app as my main navigation aid, supported by a paper map and compass for emergencies. The OL17 Explorer map covers this hike, it can be bought directly from the Ordnance Survey website here. When you buy the paper map it gives you a code that gives you free access forever to the digital version on the phone app. I have previously used the Ordnance Survey subscription service, it was amazing, but personally, I like to have both paper and digital maps for those rare times when my phone lets me down.
NOTE: The walking times in the guide are based on how long I think the average hiker would take to walk different sections of the route, it assumes you're not stopping for photos or food, etc., sometimes I'll supplement the durations with distances in meters.
1. Starting at the Ogwen Centre pay and display car park, head towards the Cwm Idwal visitors centre (see image 1); if you need the toilet, want some more info about the area, or you're just a bit peckish, head into the centre before you start the hike (see the Facilities & Hospitality section for more information). Just to the left of the centre, there are some steps leading onto a cobbled path which you should follow. The path splits pretty soon after the steps, with one path heading straight ahead and the other heading right, follow the path that goes straight until you reach a set of 5 upright stones on your left (see image 2). If you look through the hole on each of the stones you'll be able to see the mountain whose name is engraved on the front; Tryfan and Pen yr Ole Wen among others can be seen. Continue past the stones, until you reach an ornate wrought iron gate, head through it and cross the footbridge which spans the Afon (river) Idwal.
2. From here follow the main cobbled path until you reach the edge of Llyn (lake) Idwal; don't take any dirt path diversions like the one not long after the bridge (see image 3 for an overview of this section). The route from the gate to the lake's edge is around 800 meters and will take around 10 minutes to walk. When you reach the lake the path splits in 2 (see image 4), take the left path (we'll be coming back via the right path, so you'll get to cross the little bridge later) and walk along the lake's edge until you reach a stone wall with an iron gate, which you need to pass through. Continue walking along the cobbled path and eventually the lake edge will veer off to the right whilst the path continues straight ahead. Shortly after the path and lake edge diverge, there will be 2 sets of steps, the first with relatively few steps, the second set with many more steps and a more gradual incline. When you get to the top of the steps (see image 5 to see the view from the top so you know you're on the right path), there will be a low stone wall on your left, just beyond this the route splits in 2, with one heading to the left taking you uphill, and the other continuing straight ahead at the same level you're currently on, take the path that goes straight ahead (see image 6).
3. Continue for around 310 meters after the path splits (around 4 minutes walk) until you reach another split in the path, with one heading to your right towards the lake, and the other heading straight on; take the path going straight on if you want to do the full, slightly more challenging route (see image 7), or if you want to avoid this section to make the hike less strenuous or just shorter, take the path to the right and head to step 6 where it will rejoin the longer route I'll describe going forward (and see image 8 for an overview of the shortcut route). So, after heading straight on at the split, the path will start to ascend; it's still mainly the cobbled path you've been following throughout the walk, interspersed by some loose rocky sections, but it's always easy to follow (unless it's covered by snow!).
4. Continue to follow the clearly defined path, on your left you'll see the Idwal Slabs which will likely have climbers on (see image 9). Continue past this, following the path as it ascends towards Devil's Kitchen (see image 10), or Twll Du ("Black Hole") as it's known in Welsh, a dramatic gash in the mountainside that often has plumes of steam emanating from within it; according to local legend, the steam comes from the Devil cooking in his kitchen👹. Head to this Google Maps link, which will give you a 360-degree view from where you should be at this point in the hike; notice the lake behind to your right, the path you're on will soon start to turn taking you back towards it. Follow the path until you reach a bridge (see image 11), cross it and continue onwards, with Devil's Kitchen still ahead of you. You'll come to a section of the path with a big boulder in front of you. The path turns sharply to the left here (after making this left you should be able to see the gash that is the Devil's Kitchen directly ahead of you (see image 12), up to now you will have just seen it from the side on). Shortly after it will turn sharply to the right, and then finally it will gradually turn right again until it heads back towards the lake (see image 13 for an overview of this section).
5. The next part of the route has you heading back towards Llyn Idwal, and from here, the path you've been following will gradually start to descend towards it. Continue on this path for around 450m (5 to 6 minutes walk) until you're almost level with the lake and you can see the path in image 14, heading off to the right (this is where the shortcut described in step 3 rejoins the main path).
6. If you took the shortcut, turn right when the path you're on meets the main path (see image 7). If you took the longer route you're already on the main path, so continue straight ahead, going past the right turn and keeping the lake on your right-hand side. From here follow the clearly defined path running alongside the lake, until you reach the stone wall and gate as shown in image 15. Pass through the gate, and admire the stunning pebble beach, which sits directly across from Devil's Kitchen and is an amazing spot for some lunch. When ready, walk to the other end of the beach and onto the path which runs alongside the edge of the lake. The path will lead you to a stone wall with a gate which you'll need to pass through, immediately after this you need to cross the little bridge which you might remember from earlier in the hike. About 10 meters from the end of the bridge turn left (you should recognise this area from earlier in the hike [step 2]) and then retrace your steps to get back to the start of the hike.
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gallery
 Tryfan Window Stone |  View Towards Devils Kitchen |  Cwm Idwal Cloudy Vista |
|---|---|---|
 View Over Llyn Idwal |  Hiking Route Beside Llyn Idwal |  View of Tryan on Cwm Idwal Hike |
 Llyn Idwal |  Llyn Idwal Hike |  Cwm Idwal Cobbled Path |
 Cwm Idwal Hike Route |  Llyn Idwal on Sunny Day |  Pen Yr Ole Wen |
 Ornate Iron Gate on Cwm Idwal Hike |  Cwm Idwal Mountains |  Llyn Idwal View |
 Pen Yr Ole Wen Window Stone |  Llyn Idwal Lake Edge |  Llyn Idwal Island |
 View of Llyn Idwal |  Cwm Idwal River |  Devil's Kitchen |
 Idwal Slabs |  Cwm Idwal Route |  Devil's Kitchen |
 Cwm Idwal Boulders |  Cwm Idwal Route |  Cwm Idwal Bridge |
 Cwm Idwal |
hints & Tips
general
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This route is suitable for novice walkers with a good level of fitness. The trail is well-maintained but can be uneven and boggy underfoot in places.
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There are no toilet facilities on the hike itself, so be sure to use the toilets at the start point before you set off.
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Wear sturdy walking boots with good ankle support. Be prepared for changeable weather conditions, even in summer. Bring waterproof clothing, a hat, gloves, and sun cream. Also pack plenty of food and water, as there are no shops on the hike.
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The trail is well-marked, but it is always a good idea to take a map and compass with you in case of bad weather. You can also download a GPS track of the route before you set off.
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The hike can be busy, especially in the summer months. If you want a quieter experience, try to go early in the morning or during the week.
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Wild swimming is not allowed in Llyn Idwal as invasive plant species found in nearby lakes can have a significant detrimental effect on a lake’s delicate ecosystem. These species can be introduced from fragments of plant stuck to clothing, towels, dog hair etc. and transferred from lake to lake by wild swimming.
Facilities & Hospitality
Toilets, WiFI, Food & Drinks
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Cwm Idwal Visitors Centre right at the start of the hike has toilets, free public wifi and boasts a light refreshments kiosk offering a variety of hot and cold snacks. Its usual operating hours are from 9 am to 4 pm, with extended times during the summer months. However, in January, the kiosk operates solely on weekends.
Accommodation
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YHA Idwal Cottage: Located right at the start of the hike, next to the visitors centre, this youth hostel is perfectly situated for hiking in and around Ogwen Valley. YHA Idwal Cottage is self-catering but there is a shared kitchen you can use to cook meals; it also has a bar which serves a range of alcoholic and soft drinks. There is no Wi-Fi avialble. For more information and to book a room click here.
Interesting Facts
General
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Llyn Idwal and its surrounding area are home to a variety of plant and animal species, including rare alpine plants like the Snowdon lily (Lloydia serotina) and the Purple Saxifrage (Saxifraga oppositifolia). The lake also supports populations of fish and provides a habitat for birds of prey such as peregrine falcons and buzzards.
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In 1954 Cwm Idwal was designated as a National Nature Reserve, the first in Wales
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Cwm Idwal is a cirque (or cwm, see "Mountain Range & Cwm Formation" section below for more info) in the Glyderau range of mountains in northern Snowdonia
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The area around Llyn Idwal has cultural significance in Welsh history and literature, inspiring poets and writers for centuries. It features prominently in the works of Welsh poets such as Taliesin and Dafydd ap Gwilym
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With minimal light pollution, Snowdonia National Park, including Cwm Idwal, offers some of the best dark sky opportunities in the UK
The Origins of IDWAL
According to legend, the lake’s name is a lasting tribute to Idwal, the son of the 12th-century prince Owain Gwynedd, known not for martial prowess but for his intellect and grace. In an age where valour in battle was the hallmark of nobility, Idwal’s scholarly nature made him an anomaly. To shield him from the perils of war, his father entrusted him to the care of his uncle, Nefydd, a decision that would lead to heartbreak. Nefydd harboured a corrosive envy, his own son Rhun lacking the brilliance that came so effortlessly to Idwal. One fateful day saw Nefydd and the boys near the serene lake we see today, a setting that belied the darkness that would unfold. In a moment marred by malice, Nefydd betrayed his charge, pushing Idwal into the icy embrace of the waters below. As Idwal succumbed to the depths, Nefydd’s laughter echoed, a chilling testament to his vile act. The ripple of this tragedy extended far, with Prince Owain Gwynedd’s grief profound and unyielding. In a land where family ties were sacred, such betrayal was unforgivable. Nefydd was cast out, condemned to live with the weight of his deeds. In remembrance of his son, whose potential would remain unfulfilled, Owain named the lake ‘Idwal,’ a memorial etched in the annals of history.
Mountain Range & Cwm Formation
Cwm Idwal's story stretches back over 450 million years. During the Ordovician period, Wales lay beneath the Iapetus Ocean. Volcanic eruptions spewed ash and lava, accumulating on the seabed alongside sediments. Then, tectonic plate collisions squeezed and folded these layers, eventually thrusting them upwards to form the mountains we see today. Evidence of this dramatic history is visible in the fossils and the varied rock types, like volcanic ash deposits and pillow lavas formed underwater. The Cwm, also known as a corrie or cirque, owes its formation to the relentless forces of glacial erosion over thousands of years. Its steep cliffs and U-shaped troughs stand as enduring monuments to the power of natural forces, reminding us of the vast timescales and immense energies involved in shaping Earth's landscapes. For more information on Cwm formation see the below video, courtesy of Geography Simplified:
Charles Darwin
Upon Charles Darwin's arrival in 1831 to investigate what would later become his renowned yet contentious work, 'On the Origin of Species,' he encountered the initial indications of Cwm Idwal's formation. Amidst the scattered rocks and boulders, he observed minute fossils of marine organisms and oceanic flora, eloquently portraying their former existence as part of the rocky seabed of the Iapetus Ocean. This marked Darwin's first revelation. A decade later, Darwin revisited the site and came to a groundbreaking realisation that colossal glaciers had shaped the landscape; this represented Darwin's second significant discovery in the region.
