Orkney festival-goers build wall for seaweed-eating sheep

Festival-goers have gathered in North Ronaldsay in Orkney to help build a 13 mile (21km) stone dyke.

The annual event draws volunteers from around the world and includes dyke building, workshops, music and a ceilidh.

The wall is required so that the unique seaweed-eating sheep are prevented from venturing onto the grass.

An enzyme in seaweed stops the ancient breed of sheep being able to process grass and can lead to copper poisoning.