Dragon's Back Race: Is this the toughest mountain challenge?

It has been described as "brutal" and is up there with the toughest of mountain races.

The Dragon's Back Race is 200 miles (322km) long and involves 50,850ft (15,500m) in climbs.

Over five days, competitors have to get from Conwy Castle in north Wales to Llandeilo in the south.

The route covers wild trails and mountains, and also has cut off times.