Columbia subject headings:
Harvard subject headings:
Archaeoastronomy--Great Britain.
Great Britain--Antiquities.
Megalithic monuments--Great Britain
Princeton subject headings:
Archaeoastronomy--Great Britain.
Archaeoastronomy--Ireland.
Megalithic monuments--Great Britain.
Megalithic monuments--Ireland.
Religion, Prehistoric--Great Britain.
Religion, Prehistoric--Ireland.