Cwm Idwal National Nature Reserve, near Betws-y-coed

What's here


Cwm Idwal lies at the northern end of the Eryri (Snowdonia) National Park and is a popular location for mountaineering and other outdoor pursuits. 

It is an access point for the Carneddau and Glyderau mountain ranges. 

The National Trust, the Eryri National Park Authority and Natural Resources Wales work together to manage Cwm Idwal.

Visiting Cwm Idwal

The visitor centre is the ideal place to start a visit to Cwm Idwal National Nature Reserve.

There are interactive touch screen displays and a film screen that shows different views of the reserve.

There is a refreshment kiosk that sells hot and cold snacks and toilets.

The visitor centre is unstaffed but there is a warden’s office onsite and an external electronic screen showing the weather forecast.

The car park, toilets and all visitor facilities here are operated by the Eryri National Park Authority - see the Eryri National Park Authority website for the latest information.


There is a circular route following public footpaths around Cwm Idwal lake.

This is accessed from the car park, to the left of the visitor centre, via a steep and rocky path.

The walk is not signposted and is about 3.5 miles long.

There are several other walking and rock scrambling (rougher access) routes which lead up to higher ridges.

Please note: 

  • all routes are uneven underfoot
  • the terrain is difficult, even in good conditions, due to the very steep and rocky nature of the ground
  • the conditions vary dramatically with the seasons 
  • there are stiles and gates where the routes cross walls and fences

National Nature Reserve

In 1954, Cwm Idwal became the first National Nature Reserve in Wales.

National Nature Reserves are places with some of the very finest examples of wildlife habitats and geological features. 

There are over 70 National Nature Reserves in Wales.

Find out more about National Nature Reserves.

Geology of Cwm Idwal

Visitors can see the most graphic evidence of how this landscape was created at Cwm Idwal.

The folds and faults are the direct result of the tumultuous forces which pushed up these mountains 450 million years ago.

The much more recent Ice Age sculpted and gouged their cliffs and ridges, as well as the great amphitheatre of Cwm Idwal itself. 

On all sides you can see the legacy of the huge glacier that once filled this space - the hanging valleys of Cwm Cneifion and Cwm Clyd, the massive, polished boulders, the moraine at the lip of Llyn Idwal, the huge scree slopes and, most remarkably of all, the jagged rock formations on the summit plateau of the Glyderau.

Wildlife at Cwm Idwal

Even the plants here are survivors from the age when ice was king. 

On the ledges, beyond the reach of the feral goats, there are a host of rare arctic alpine plants, including the moss campion, Snowdon lily, alpine lady’s mantle and purple saxifrage.

Seasonal highlights

During the year, the landscape changes at Cwm Idwal National Nature Reserve.

Depending on when you visit, you are likely to see different wildlife, too.

Read on to find out what you could see here during the different seasons.


In the spring, the rare Snowdon lily and other montane plants come into flower.


Migrant birds such as the ring ouzel and wheatear make Cwm Idwal their home during the summer.


Autumn brings shorter days and a range of heathland colours.


In the colder months of late winter through to early spring, flowering purple saxifrage brightens up the winter landscape.

Eryri (Snowdonia) National Park

Cwm Idwal is in Eryri (Snowdonia) National Park.

Eryri is the largest National Park in Wales and is home to picturesque towns and villages and the highest mountain in Wales.

It is looked after by the Eryri National Park Authority.

For more information about visiting Eryri go to the Eryri National Park Authority website.

Closures and diversions

  • Sometimes we need to close or divert trails for your safety whilst we undertake maintenance work or other operations.
  • We may have to close a site in extreme weather, such as high winds or snow and ice, due to the risk of injury to visitors or staff.
  • Please always follow any instructions on site and any temporary diversion signs.

How to get here


Cwm Idwal is 10 miles west of Betws-y-coed on the A5. 

This site straddles the county borders of Gwynedd and Conwy.

Ordnance Survey map

Cwm Idwal is on Ordnance Survey (OS) map OL 17.

The OS grid reference is SH 649 604.


The main car park for Cwm Idwal is the Llyn Ogwen car park which is managed by Snowdonia National Park.

Turn off the A5 at the sign post for the youth hostel.

Sustrans cycle route 85 runs from Bangor to the Cwm Idwal car park.

Public transport

The nearest train station is in Betws-y-coed or Bangor.

The S6 bus runs along the A470 between Bangor and Betws-y-Coed. 

For details of public transport visit the Traveline Cymru website.


The main car park for Cwm Idwal is the Llyn Ogwen car park.

There is a charge for parking in this car park.

This car park is operated by the Eryri National Park Authority.

See the Snowdonia National Park Authority website for the latest information about the car park.

Other places in North West Wales

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