Marcel Mestdagh, (1926-1990) was a Belgian historian whose curiosity was sparked by a discovery of unusual street patterns in the Belgian city of Ghent. This led to a lifelong interest in the Viking culture that had settled on both sides of the English Channel. It was this study of the Vikings that led him to realise that they had knowledge, now forgotten, of the purpose of many of the megalithic monuments which Mestdagh identified as a form of road system, laid out in giant ovals with radials. At the centre of these ovals was the ancient city of Sens where the greatest concentration of megalithic monuments in France existed.
Philip Coppens informs us[1275.184] that a further strange discovery by Mestdagh was that the ancient road network he identified, centred on Sens, was mirrored by a similar network of roads in England centred on Nottingham!
In the course of his investigations Mestdagh discovered an aspect of the Stonehenge-Avebury complex that had been overlooked, namely that the two sites were situated on the circumference of a huge oval. He further discovered that this oval was on a scale 1/10th of the ovals that he had discovered in France.
The late Filip Coppens, following Mestdagh’s work, has persuasively argued that Atlantis was the centre of a far-flung megalithic civilisation with its centre located where the ancient city of Sens now stands. Coppens returned to Mestdagh’s theories in his 2012 book,The Lost Civilisation Enigma, which in turn led to two supportive essays from Bruce Jeffries-Fox in 2015*(c)(d), who includes the observation that while Coppens was initially happy to follow Mestdagh and identify Sens as Atlantis he executed a volte-face and declared that “from c. 4500 to 1200BC, a major civilization existed in Europe about which we know very little.”*
A YouTube clip(b) also gives some idea of Mestdagh’s theory.
(a) https://www.kunstgeografie.nl/mestdagh1.htm (Dutch) (offline Dec. 2015)