Do Orcadian Tombs Align with Solar Events ?


Research conducted by Andrea Boyar BA, Post Graduate student at The Archaeology Institute, University of the Highlands and Islands, Orkney.


Orkney forms one of the most intensively studied regions in Britain, providing a ‘core area’ for research (Barclay 2004: 34-37). The aim of this study was to establish to what extent Neolithic cairns in this region align with solar events

Research Objectives

  • Determine the orientation of the entrance passages of the Orcadian chambered cairns.
  • Establish trends within the range of orientations.
  • Analyse the extent of alignments that fall into the range of orientations.

Background Context

The funerary monuments of Neolithic Orkney are characterised by stone-built burial mounds situated near water, perhaps indicative of the importance of sea migration (Phillips 2003: 384). These cairns contained inhumations and cremations reflective of collective burial practices, in addition to an assortment of animal bones, stone tools, pottery, and other grave goods (Davidson and Henshall 1989: 52-59). The monuments appear to have been in use for a few hundred years, and there is a “strong possibility” that many were re-used before being deliberately decommissioned (Lee 2011: 43).

Types of Neolithic Cairns in Orkney

Orkney Carin types

Case Study: Rousay

Rousay orientation.png
Distribution map of the Rousay chambered cairns, showing orientation of entrance passages acording to azimuths measurements

The island of Rousay was selected for a case study due to a high concentration of well-preserved burial architecture. The primary fieldwork aim was to record cairn azimuths in order to measure deviation from solar alignments. Key to this analysis was Stellarium, an open source planetarium used to establish the Sun’s position in the Neolithic period in Britain. By utilising precise measurements, rather than relying upon cardinal point orientations, this approach allowed for a more temporal conclusion to be reached on the relationship between solar alignment and mortuary architecture in the Neolithic.

Project Results

Azimuth results
Azimuth of Rousay Cairns

Orkney-Cromarty cairns were predominantly orientated towards the southeast, with an avoidance of northern orientations

Maes Howe cairns were more variable; there appears to be a shift from the southeast to the southwest, with a complete avoidance of the north

Hybrid cairns were the most random, containing northern orientations within examples of atypical subterranean architecture

Project results

Research Findings

  • Early Neolithic cairns placed an importance on the Midwinter sunrise, while late Neolithic cairns exhibited a shift towards the Midwinter sunset
  • An avoidance of a northern orientation, which would theoretically place a tomb in a state of perpetual darkness
  • The outlier cairns orientated to the north demonstrated atypical subterranean architecture, perhaps indicative that these specific tombs were built to intentionally keep light out of the interior
  • Azimuths provided a temporal range for illumination periods – an area of further research

Further Research

Considering how this study has evidenced seasonal intervals beyond the solstices as significant, it would be worthwhile to look at how times of illumination may relate to periods when Neolithic Orcadians would visit a tomb, inter their dead, and manipulate the remains. Applying the methods utilised in the Rousay case study to the rest of the region may reveal further insight relating to the temporal function of astronomy in Neolithic Orkney.


Neolithic Orcadians were an agrarian society, and as such, the changing seasons would have played an integral role to the sustainability of their way of life. For reasons unknown, solar alignments were incorporated into burial architecture; with a focus on the Solstice period, a time when one cycle ends and another begins. It is possible that sunlight was simply useful for physically seeing inside the chamber itself, however, it appears that these alignments reflect an underlying cosmology indicative of the cultural importance of the sun to an agricultural community. Cairns are mortuary structures, thus the alignments evident within them may reflect pivotal periods in the year associated with ancestral rebirth or renewal