Cwm Idwal is tucked in on the north side of the Glyderau mountain range at the junction of the Ogwen Valley proper and the glaciated trough of Nant Ffrancon. It is possible to get a taste of the mountains here, but without committing to a high level walk. A stone-pitched path leads up from the visitor centre to the edge of Llyn Idwal. The view along the Ogwen Valley to the striking ridge back of Tryfan is stunning, as is the view back down Nant Ffrancon and out to the coast and Anglesey.
The cwm itself is both rugged and grand; this natural amphitheatre is littered with impressive crags. Most striking is the sweeping form of the Idwal Slabs, a huge swathe of smooth-looking rock which is very popular with climbers. During a cold winter snap huge icefalls form on Clogwyn y Geifr, the dark crag which sits at the back of the cwm.
A circuit of the lake takes you round past the base of the Idwal Slabs and back to the head of the lake where there is an alternative route back to the visitor centre via a narrow, quarried ravine.
The walk can easily be extended with a circuit of the nearby Llyn Ogwen. This is well worth doing if you have the time as it allows for a number of different perspectives on this spectacular valley.
There is a car park at the Ogwen Cottage visitor centre, plus various parking areas alongside Llyn Ogwen.
Mostly good footpaths but rough in places. The paths leading up to and around Llyn Idwal can become very slippy if there is snow on the ground.