Picture courtesy National Library of Scotland

Dennis Ness and Dennis Head

Dennis Ness and Dennis Head, North Ronaldsay
A former kelp pit at Dennis Head, with some of its stone-lining exposed. Again, the differing colour and flora within the pit aides in its identification. (📷 ORCA)
Fig 1: A former kelp pit at Dennis Head, with some of its stone-lining exposed. The differing colour and flora within the pit aides in its identification. (📷 ORCA)

The kelp workings at Dennis Ness and Dennis Head mainly comprise kelp pits with a small number of tangle dykes. These were an essential part of the kelp processing industry which thrived in Orkney during the late eighteenth and nineteenth centuries.

Dennis Ness forms the north-east headland of North Ronaldsay, between Torness and Westness. The workings cover an area from Dennis Head in the south to Ires Taing and Trolla Vatn in the north (NGR HY 78864 55198 to HY 78145 56106).

Recording of the site was undertaken by the ORCA team and local volunteers in September 2024.

Fig 2: A kelp pit at Dennis Ness, North Ronaldsay with the lighthouse in the background. The outline of the pit interior is clearly discernible by the greener colour of the grass and the presence of flowers, in contrast to the surrounding ground surface. (📷 ORCA)
Fig 2: A kelp pit at Dennis Ness, North Ronaldsay with the lighthouse in the background. The outline of the pit interior is clearly discernible by the greener colour of the grass and the presence of flowers, in contrast to the surrounding ground surface. (📷 ORCA)

In total, some 64 kelp pits and three tangle dykes were recorded. Today, the kelp pits survive as circular depressions within a generally flat ground surface, often with more abundant or varied flora (Fig 1).

Most of the kelp pits had stone components, and a stone lining was occasionally visible (Fig 2). The pits varied in size from 1.5m to 3.2m in diameter and were generally 0.19m deep.

Fig 3: The remains of one of the three tangle dykes recorded at Dennis Ness, North Ronaldsay. (📷 ORCA)
Fig 3: The remains of one of the three tangle dykes recorded at Dennis Ness, North Ronaldsay. (📷 ORCA)

A group of three tangle dykes, built using coursed masonry (Fig 3) were identified above the coastal section at Versa Geo. Measuring between 3.4m and 4.3m in length and all 1m wide and c. 0.35m high, two of the dykes were orientated parallel to the shore and the other perpendicular to it.