This is a linear crossing of southern Snowdonia, between Barmouth on the west coast, and Llangollen in the east. The original concept was E-W, linking 7 trig points, and ending at the sea. Lovely!

This would be suitable for someone looking for a full-daylight challenge, not a full 24 hours, perhaps as a training run for a Bob Graham or similar, or a great challenge in its own right. 58 miles (93km) and some 15,000 feet (4,500m) ascent.

Some key info first, and then a brief account of the fun that was had:

• There is a bus service between Llangollen and Barmouth with (in 2024) cost a whacking £4.50 for a single ticket. For logistics, particularly on a solo venture, it seemed easier to run W-E, catching the bus at the start and running back. But E-W is traditional, and I think would be better. There are also options to include extra high points and/or trigs.
• The target time is 18 hours (took me 15:42), which fits into daylight IF you work the logistics correctly. Having a driver, or an overnight stay before and after, would make this a lot easier. My run was a bit spontaneous and I like using public transport, but it did mean a dark finish!
• The running is mostly good and glorious. Some of it is rough underfoot, as some of these hills are not well trodden. And I have to mention the Hirnant hills, where almost nobody goes. There is a track for much of this section, but where there is no track, the going is very difficult indeed – waist-high heather, tussocks and bog.
• There are no amenities en route, but there are numerous road crossings, at before and after every group of hills. The hills are predominantly dry, but there’s water somewhere between each group.
• W-E the principal points are Cadair Idris, Waun-Oer, Aran Fawddwy, Foel y Geifr, Foel Cwm-Sian Llwyd, Cadair Berwyn, Moel Fferna. Additional trigs others have added (for relatively minor extra distance) are Pen Y Garn near Barmouth, and Y Foel near Llangollen.

The adventure started by wandering around Llangollen, trying to find the bus stop. Llangollen isn’t busy at 7.30am, and nor was the bus – but the 2 hour journey across Wales was beautiful. I had to change bus in Dolgellau at what looked like a slick operation with numerous buses and arriving and leaving to permit different journeys. Does it work this well when the roads are busy? Who knows. I departed Barmouth around 9.30, crossing the beautiful bridge and ascending onto the western end of the Cadair Idris group.

This was by far the busiest section of the route, lovely flowing ridges, ending with a pretty abrupt drop off Gau Graig to the main road. On the other side of that road, I saw very few people until wild campers on the Berwyn. The short section over Waun-Oer and its satellite hills is quiet and beautiful, mainly grassy with just a few rough sections. Then, a long trek up to the Arans, on faint grassy trods over the summit of Glasgwm (with its strange high pond). Turning east from Aran Fawddwy, the terrain changes pretty soon, as steep rugged mountains give way to something that feels more like the remote areas of the Peak District. I went over the summit of Hafod-fynydd because it looked nice, and after a secluded valley (welcome water) and a steep climb, suddenly it was like being lost on Bleaklow.

There was a fence line with a vague trod of sorts, over the flat plateau of Clipiau Duon. I had wondered about taking a line further NW, where the hillside steepens, on the basis the terrain might be easier and drier. But I got drawn to the fence and through the predictable peat-hags. It made slow going, some of the flattest but slowest miles so far. After Bwlch-y-groes there was briefly a path, and then the Hirnant terrain took over – marsh, tussocks, ticks! In places, quad tracks made it easier, but generally there was nothing on the ground, and it was a flashback to the hardest Mountain Marathons to get through tussocks followed by thick heather to Foel y Geifr. The downhill from there was better, and then the track was reached,

The track! I read a report which called it “the interminable track”. It does go on a bit, but imagine if it wasn’t there. This is proof that fellrunners before masochism to boredom any day. I actually found the track fairly pleasant, the evening views over wide open Wales were stunning, and it was satisfying to actually tick off some miles again rather than wading through undergrowth. Unfortunately, it ends about 2 miles too soon, leaving another heather-wade followed by an ephemeral trod to Foel Cwm-Sian Llwyd. That trig was reached with relief, and then a long, runnable descent took me to the road and entry to the Berwyn Hills.

And suddenly, it was all beautiful again. It was now late evening, on a steady ascent over Moel Sych to Cadair Berwyn, where plenty of tents were set up for a stunning starlit night. The going was much easier, sunset fell over the highest tops, and then a dark descent north from Cadair Bronwen. On a previous long run around here, I remember thinking it felt a really long way over long heathery hills between there and Moel Fferna, and so it was again. At least there was a path this time. Easier going from Moel Fferna to Vivod Mountain, followed by a long steady descent to Llangollen. The pumping music emanating from a pub seemed a bit out of place!