Carnedd Llewelyn & Carnedd Dafydd loop from the Ogwen Valley — Eryri (Snowdonia) National Park

This difficult 9.2-mile (14.8 km) loop, with its 2978 feet (908 metres) of elevation gain, typically takes around 2 hours and 16 minutes for experienced joggers. You will encounter varied and strenuous terrain, including stony ground, rocky sections, and steep ascents and descents. The route offers spectacular panoramic views across northern Snowdonia, allowing you to see the majestic Glyderau and Tryfan ranges, as well as views stretching to Anglesey. You will also pass above the impressive cliffs of the formidable Ysgolion Duon, known as the Black Ladders.

This trail is highly challenging and is only suitable for experienced mountain runners. You will need very good fitness, sure-footedness, sturdy shoes, and alpine experience to complete it. Route-finding can be difficult, especially if fog rolls in, and poor visibility can significantly increase the challenge and risk. Be prepared for scrambling sections, particularly on the initial climb up Pen yr Ole Wen.

The loop is notable for encompassing Carnedd Llewelyn, the second highest peak in Wales, and Carnedd Dafydd, the third highest. It offers a more solitary mountain experience compared to the often-crowded Snowdon, allowing for a deeper immersion in the wild mountain landscape. The route is part of the "High Carneddau," which forms the largest area of high ground in England and Wales, providing vistas of deep cwms and lakes like Ffynnon Lloer.