This study examines Sysa Hillock as a complex astronomical site, serving both as an observatory and a centre for solar and lunar worship. Its significance, rooted in the Neolithic period, is demonstrated by its alignment with celestial events. Sysa's influence continued into the Viking Age, as reflected in myths like the Prophecy of Audna, where twelve Valkyries weave a web of twelve sections. This myth is shown to enshrine Sysa's central role in both ancient astronomical practices and the organisation of territorial space.

Following an interpretation of the astronomical and cosmological themes expressed in the architecture of Cambodia's Angkor Wat temple complex, a potentially significant 10th-century dynastic prime meridian is delineated, and its use in determining the precise location of Angkor Wat is posited.