Llwybr Llechi Eryri (Snowdonia Slate Trail)

This is a point to point walk, not a loop: it runs from Bangor on the coast to Bethesda, and the official total is 83.4 miles (about 134 km) split into 13 manager-defined sections. The complete route is described as a seven day walk, which works out at roughly 48 hours of moving time, so plan slower days for the longest and roughest stages plus time for stops and transport. Because it ends in Bethesda rather than back at Bangor, you need to arrange your own return travel.

The first day out of Bangor is easy and slate-focused, a gentle way to start. After that the mix is lanes, forest and forestry tracks, riverside paths, minor roads, steep climbs and rough open moorland. Nantlle to Rhyd Ddu has a very boggy stretch, and Llan Ffestiniog to Penmachno is the toughest section, with the gorge, wild and sometimes boggy Migneint, quarry workings and real route-finding. Croesor to Tanygrisiau also needs careful navigation to reach Rhosydd. Expect wet feet in places, carry a map and compass and know how to use them, and be honest with yourself about the roughest days rather than trying to compress them.

The trail uses public rights of way or permissive paths, crosses rough and remote ground, passes right next to disused quarry workings, and includes sections of minor road where you share space with traffic. Some of the surrounding land is privately owned with no general public access, so stay on the signed route. Mobile coverage is patchy, which matters most on the moorland and quarry sections. Dogs are welcome under park guidance on public footpaths and open access land, but they must be under close control, on a short lead near livestock and wildlife, and on a lead of no more than 2 m on open access land from 1 March to 31 July. Private and permissive stretches will not all follow identical rules, so read signs as you go and assume stricter is safer.

The stored trailhead is the Bangor Beach Road trailhead, near 53.231821, -4.110714. The Beach Road public car park sits a short way from the start and is free, but no overnight parking is allowed, and parking at the trail itself is private, so a multi-day walker is better off leaving the car at home and using public transport. Transport, accommodation and refreshments all need booking and planning in advance rather than improvising. There are no shops between Llanberis and Beddgelert, so carry food and water for that stretch. Conwy Falls Cafe sits on the Penmachno to Betws y Coed section, and the larger villages give you the best chance of resupply.

If you only have half a day and want the slate story without the logistics, the 5.5 km Croesor Circular is the better fit. Choose this trail when you actually want the multi-day crossing, coast to quarry town, with all the planning that involves.