Knowth passage-grave in Ireland: An instrument of precision astronomy?

Abstract

Knowth is one of three large monuments at the Neolithic complex in the bend of the River Boyne in County Meath, Ireland. The others are Newgrange and Dowth. All three have obvious solar alignments but whereas the alignment to the winter solstice sunrise at Newgrange has been extensively researched and interpreted, little has been attempted regarding the way that astronomy functions at Knowth and Dowth. This paper treats the evidence for solar and lunar alignments at Knowth.

Knowth has two internal passages with entrances at the east and west. The paper draws on new surveys as well as interpretations of the evidence at Knowth that includes rock art engraved on kerbstones around the circumference. Particular engravings on kerbstone K52 are interpreted as depicting astronomical cycles. It is argued that, while Knowth’s passages function in relation to the equinoxes, they are not internally orientated to match exactly the equinoctial directions. Rather, it seems that they may have been constructed and used to facilitate the harmonisation of the solar and lunar cycles - much in the same way as does the equinoctial Judeo-Christian festival of Easter. The paper concludes by suggesting that like Newgrange, Knowth may be an astronomical instrument that enabled its builders and users to construct accurate calendars and counting systems, which in turn facilitated calculated planning and was a fundamental structuring principle for their ritual lives and cosmological beliefs.