If you’re looking for a tough but incredibly rewarding day in Eryri (Snowdonia), this route up Pen yr Ole Wen (978m) with the option to continue to Carnedd Dafydd (1,044m) ticks all the boxes. Expect steep climbs, rocky scrambles, and breathtaking views. This is a walk for experienced hikers (and confident dogs).

The walk begins gently, following a stream through farmland. This lower section can be boggy, but there are usually stepping stones to help you across. As the path climbs higher, the terrain quickly changes — grass gives way to boulders, scree, and steep rocky gullies. One gully in particular is a real challenge, requiring hands-on scrambling and a good head for heights. Dogs may struggle here — even Riley, who is used to Welsh mountains, needed careful guidance and support. Carrying them isn’t really an option, as the space is too narrow and tricky.

Once you’ve gained the summit of Pen yr Ole Wen, the reward is immediate. Views over Tryfan, Ogwen Valley, and across the Carneddau range are absolutely spectacular. From here, the path continues along a broad ridge to Carnedd Dafydd. It’s far less technical than the ascent, though conditions on the tops can be very different to the valley below. Be sure to pack extra layers, as wind speeds can be fierce even on an otherwise calm day.

From Carnedd Dafydd, you’ll be standing on one of the highest peaks in Wales, with panoramic views stretching across the entire national park. It’s a truly unforgettable spot to pause, refuel, and soak up the landscape.

If you feel that descending the same way, especially navigating the gully, might be too much for you or your dog, there is a circular option. This route drops down the far side of Pen yr Ole Wen and follows the road along the lake back to the car. However, be prepared for very steep scree on this descent.


This is without doubt one of the more demanding routes in Eryri, with steep, sustained climbs and sections of real scrambling, but if you’re up for the challenge it’s also one of the most rewarding days you can have in the Welsh mountains.