Three particularly noteworthy examples of these cairns are: All have narrow rectangular chambers whose positions are marked by wooden posts.
Although none of the northern cairns has been excavated, their existence is significant for the architectural history of Scotland.
The north is a region where passage tombs in circular cairns are especially common (the Orkney-Cromarty type).
Sites that span several periods of time, such as Tulach an t'Sionnaich, demonstrate that both forms were used by the same communities.
Many chamberless cairns and those with stone chambers have concave forecourts which are reminiscent of those that had been built earlier of wood (Haddenham and Street House) in Yorkshire.