Coming towards the broch from Lyking, where the Burn of Lyking passes under the field wall (nice double bridge in drystane), I saw a short line of good stones along the bank running to the fieldwall at an acute angle. There appear to be remains of another bank wall over in the broch field section of the stream too. Going in for a closer look at these I saw that there is an earthwork with stones, taking the shape of a circular quadrant (HY27121514) rising from the burn, occupying the field corner this side of Lyking against a loop of the stream [it may be relevant that CANMAP shows mound of the Viking burial as having been in the next loop, north of this]. There appears to be an inner ditch below the top of the rise and the mound's arc appears to continue on the other side of the road, though no earthwork is shown there on the first O.S. map. In 1882 a ford is shown at this area of the burn and the subterranean passage is indicated downhill from this area.
Though this would appear to be a continuation of the broch settlement it is not presently recorded and may instead relate to a vanished mound from which a Viking burial came (RCAHMS NMRS record no. HY21NE 4). This is currently indicated on CANMAP at HY271152 but does not appear on the 1882 map like the Viking cists do (HY21NE 8 at HY27051532, but on the 1182 O.S. at HY26961532), unlike this earthwork.