On the north and north-west of the main trench, lies a substantial belt of building remains and features that we have called the Structure B complex.
This zone partly overlies the top of the remains of the broch (Structure A), as well as spreading beyond it. There are rectilinear and cellular building remnants, with many well-preserved hearths, stone fixtures and fittings, thresholds, wall piers and floors. Often, these various elements can be seen to relate to each other in a complex manner, with successive features cutting and partly demolishing earlier elements. It brings to the fore the rich story of social change that almost certainly lies behind the fairly frenetic changes that have taken place across the Structure B area.
The area has yielded numerous small finds, including substantial amounts of pottery, stone tools, an extensive animal bone assemblage, gaming counters, as well as a number of striking metal items, including numerous knife blades. Perhaps most bizarrely, a carved stone object in the form of a human head (pictured right) came from the infill of Structure B2.
We now know that this post-broch settlement began at some point between the mid-3rd and 4th Centuries AD. How long it lasted into the Late Iron Age/Pictish period is not clear yet but archaeomagnetic dating shows us that the main hearth in Structure B1 was last heated sometime after AD500.
One of the most remarkable aspects of B1 is its very large, formal and complex central hearth, which was over three metres in length in its fully developed form. This mega-hearth, and the central location of the building directly juxtaposed with the remains of the abandoned broch suggest it was one of the key buildings in the immediate post- broch period at The Cairns.
It may have held the highest status on site at that time and may be the successor to the central broch in socio-political terms.
Pushing this further, it is tempting to speculate that it was the important and powerful household resident in Structure B1 who instigated and organised the production of the jewellery, and the feasting, with all the capacity that those remarkable objects and events had for the creation and maintenance of the post-broch Iron Age community at The Cairns.