An ancient structure that plays a vital role in the preservation of a rare breed of sheep.

North Ronaldsay is Orkney's most northerly community and one with a very distinct character and heritage. It's also famous for its flock of seaweed-eating sheep. The North Ronaldsay breed spends the vast majority of its time on the island's rocky shore, feeding on seaweed washed up by the surrounding sea.

They're kept off the grassland by the Grade A listed Sheep Dyke which encircles the entire island. It was built in the 19th century and is a very special structure indeed. The dyke follows the coastline and features stone 'punds', used to gather the sheep for shearing. It also suffers greatly from winter storms, with large, fragile sections collapsing during severe weather.

Maintenance is an ongoing challenge for the local population. Without the dyke, the future of the flock would be at risk, and the sheep are vital to the economy of the island. The wool is processed by a special mill housed in the island’s lighthouse buildings, while the mutton is much-prized by leading chefs.

To help, the island's annual Sheep Festival aims to raise awareness of the breed and the dyke itself.

North Ronaldsay is a fascinating place to visit, and a walk around the shore lets you see the dyke at first hand. You can also volunteer some of your time to help rebuild it too, providing the chance to give something back to this unique community.