At www.uea.ac.uk/~jwmp/CAA2003.pdf (or http://tinyurl.com/pjs8vz3) we have a paper released by the University of East Anglia on a significant henge in Norwich. It is situated near the junction of the rivers Yare and Tas, less than 4km from the city centre. It is one of several prehistoric monuments, most of which date to the Bronze Age. Arminghall henge is Late Neolithic (sometime during the 3rd millennium BC). It was discovered from the air in 1928 and investigated in 1935 – and more comprehensively a few years ago. Norfolk is a fairly flat country in the grand scheme of things but it does have hills. The view from Arminghall to Chapel Hill (which lies at the end of a long spur between the two rivers) SW of the monument, seems to take in midwinter sunset and the summit of Chapel Hill. John North, in 1996, recontructed the axis of symmetry of a horse shoe arrangement of large wooden posts within the inner ditch – but apparently it is now regarded as unreliable, as some kind of mistake was made.
The new research began in order to rectify the error in alignment, to find out if Chapel Hill was really the focus of interest. A new, thought to be more accurate study has been made, in order to discover if the henge builders were interested in mid winter sunset. The work involved in doing this is described in detail.
In the third millennium BC the last flash of the setting midwinter Sun rolled down the RH side of the hill. They achieved this fact by using Ordnance Survey mapping and measured the height of the rays emanating from the setting Sun. The altitude of the Sun was as important as the topographical lie of the land. They used a spreadsheet, and made use of John North's methodology, and the result was that in 3000BC the setting of the midwinter Sun passed the side of Chapel Hill – which was a surprise in one way (as the summit had been thought to be the focus of interest). Was there something else they were looking at on the summit?
However, the phenomenon of alignments involving the Sun rolling down the side of a hill as it sets is known from elsewhere – see for instance www.carrowkeel.com/sites/croaghpatrick/reek2.html which has the same thing at the iconic conical hill of Croag Patrick. Paul Devereux has recorded some examples of the phenomenon in various books he has written – so it is not unusual. This may also indicate the site of Arminghall Henge was important even before the monument was built – somewhat like Stonehenge (in use during the Mesolithic era). The phenomenon also explains why the henge was built on such low ground. Only from such a position, in Norfolk, can hills be utilised to effect.
At this point computer software came into play. The maps were digitised in a CAD application (used in technical drawings such as electrical wiring diagrams, and the planning of room and equipment layouts) and the results were transferred to Surfer (a software that creates Digital Terrain Models), and all this is duly described in the text. It was found there was also a double circular ditch monument at the foot of Chapel Hill which would have been positioned to view midsummer sunrise visible to the NE, over a hill on the south side of the Yare valley. They also came up with some ideas on Seahenge, the strange circular contraption of closely spaced posts hiding an upside tree at the centre, saying it may have been part of a larger complex of monuments. Seahenge was dug out of the tidal zone of North Norfolk and appears to be quite different – but it presumably had an alignment. See also http://collection.nlc-bnc.ca/100/200/300/ont_archaeol_soc/annual_meeting…
The authors, Willem Beex of the National Museum for Antiquities (Netherlands) and John Peterson, School of Information Systems, University of East Anglia, made use of John North's prior work on alignments. He is the author of 'Stonehenge:Neolithic Man and the Cosmos' Harper Collins:1996 which is rarely quoted yet is a comprehensive study of a number of monuments across the UK, from the respect of alignments (suspected and conjectured). It is the fact that some of these alignments, and the dates produced, that have led to North's marginalisation. Howevr, in general he provides an alignment not at just one point in time but picks out alignments that may have been made in several widely spaced periods of time. Also, he goes further than your average astro-astronomer by suggesting that bright stars and clusters of stars were also a feature of interest. These include the Pleiades and Orion, for example, and Pegasus and Leo etc.