[1] The Knowe of Swandro site is located directly on the beach and is being rapidly destroyed by coastal erosion.

[3] The site was initially thought to be the remains of a broch since only the mound was visible, but the surrounding structures were discovered in 2010 by Dr Julie Bond when she spotted the worn, partially-buried uprights that formed part of a prehistoric building while walking along the beach.

[4] Because of its location directly on the boulder beach, the Knowe of Swandro site is being rapidly destroyed by coastal erosion.

Despite the constant erosion, the archaeology has survived surprisingly well thanks to the boulder beach, which has provided some level of protection to the deposits and architecture below.

[5] Rising sea levels and an increase in the frequency and intensity of stormy weather systems as a result of climate change are exacerbating and accelerating the process.

Animal bones with evidence of butchering may be an indicator that feasting and similar high-status activities occurred in the settlement.

Additionally, in the fields beyond the site are anthropogenic soils, which indicates long term human inhabitation and cultivation.

In 2019 extensive surveying was undertaken and these techniques were used to collect data at multiple depths to gain a better understanding of the site.

The data yielded by the ground penetrating radar did not give a solid measurement of the depth of the archaeology, but it did show that there were more buildings concentrated around the mound.

It also indicated the presence of water in lower archaeological layers, information that is vital to the management of the Knowe of Swandro and similar sites.

The detailed earth resistance survey indicated that the large central roundhouse was surrounded by subsidiary buildings, which suggests the settlement was a nucleated village.

The lessons that are being learnt about the erosion processes and their effects on archaeology will help in understanding and mitigating the risks to similar sites.

[1] The most immediately visible feature of the Knowe of Swandro site is the eroding mound which covers the central roundhouse and a possible chambered cairn.

The mound stands about four meters from the shoreline and is so close to the shore that the water level at high tide regularly reaches its outer walls.

In 2015 the cairn was completely scanned with a 3D scanner by Dr A Wilson of the University of Bradford and aerial photos were taken by Robert Friel and Lindsey Kemp.

Much of the lower, seaward side of the outer casement wall had been removed by the sea thanks to heightened wave activity during the winter.

[9] Evidence of similar mezzanine floors dating to the Middle Iron Age was found at the Old Scatness site in Shetland, supporting this possibility.

Underneath Structure 1 there are deposits that, while severely eroded, are rich in environmental material which have provided some information about the crops grown in the settlement at Swandro.

Manmade artefacts have also been found in these deposits, like Early Iron Age pottery and a seal tooth pendant.

The curved line of orthostats, along with the placement of a door sill, indicate that the entrance to the structure was on the western side of the building.

[11] A rectangular tank made of stone was found inside the building under the flagstone floor, as well as evidence of metalworking.

[9] In 2017 the flagstones were removed and the sequence of ash, mixed ‘midden-like’ material, and stone packing beneath the building was investigated.

[8] Structure 3 is an Iron Age building that dates to the first century CE, though it was originally thought to be Pictish due to its semi-subterranean nature and evidence of sophisticated metalworking.

[12] An abundance of metalworking material has been found in and under Structure 3, including mould fragments, slag, and hammer scale form smithing.

In the lower levels of archaeology beneath the rubble infill slag, small crucibles, and mould fragments were found along with evidence of copper alloy.

More evidence of metalworking was found in 2017 during an investigation aided by archaeometallurgist Dr Gerry McDonnell, including part of a tuyère made of fired clay.

This plastic fragment was likely forced in by the pressure of tidal and storm surges, which are simultaneously removing finer particles from the archaeological sediments.

[12] The roundhouse was monumental in proportion and was likely an important site in the settlement from the time of its construction through to the Late Iron Age.

[14] After the building collapsed it was infilled and the material used to do this shows evidence of a Viking settlement, including several cat skeletons and a tiny coin of Eanred, King of Northumbria.

In addition to the houses themselves, in the 19th century a Viking age sword was found while ploughing was taking place in a nearby field.