Columbia subject headings:
Cairns--Scotland--Caithness.
Caithness (Scotland)--Antiquities.
Neolithic period--Scotland--Caithness.
Harvard subject headings:
Caithness (Scotland)--Antiquities.
Excavations (Archaeology)--Scotland--Caithness.
Megalithic monuments--Scotland--Caithness.
Neolithic period--Scotland--Caithness.
Passage Graves culture--Scotland--Caithness.
Scotland--Antiquities.
Princeton subject headings:
Caithness (Scotland)--Antiquities.
Neolithic period--Scotland--Caithness.