Archeo-astronomy

I have been corresponding with Harry Sivertsen.  Harry is an amateur archeo-astronomer and writer who uses the astronomy programs Skymap Pro and Starry Night Pro to analyse the rising and setting of the sun, moon and stars at different dates in antiquity.  It is early days, but the results are pointing towards a date of around 2500 BCE, the transition from the Neolithic to the Early Bronze Age, for the establishment of these alignments.