The fact is that if you draw a straight line anywhere on the map of any country it can easily pass through or near numerous locations of all kinds, modern, old or ancient, to which one can assign a chosen significance: for example, churches allegedly built on the location of ancient sites, etc.
There are millions of Earth locations.
An alleged line of alignment here or there alone proves nothing.
Land survey only works in an integrated system which has main triangulation points. I know. I surveyed land in my college days as summer work. If such ancient straight-line alignments existed it should be possible to reconstruct the triangulation system to which they belonged, and such a system would have to be consistent internally.
As an example, take a look at what appears to this observer to be a clearly trigonometric land survey Luvian (Luwian) symbol in Anatolia:
From the Minoan Aegean Sign Concordance we can see that mainstream Luvian scholars currently read that ancient sign as TANA, but we suggest to those scholars they take a look at Sumerian GANA "field, area (geometric figure)":
Is that Luvian symbol "evidence" of the use of trigonometry and geometry in land survey by the Luvians? It most certainly looks like it.
See surveyors.com for Land Survey Formulas.
The Luvian symbol is a simple triangulation grid, but nevertheless not unlike land survey by trigonometry in the modern period, as for example in this triangulation map of Great Britain (Ordnance Survey © Crown Copyright NC/2004/35281), as linked from Trig Tools (go to that site for a more detailed explanation):
As written at Heritage and History, 6500 triangulation pillars were erected for that survey in the modern era, not counting the half-a-million or so "bench marks and levelling points" of which about half have already disappeared, as the era of GPS has taken over.
Did the ancients do a comparable triangulation many years ago with the tools then at their disposal?
I do think, based on my research (see megaliths.net) that seafaring ancients surveyed the Earth thousands of years ago -- or at least parts of that Earth, but I think they did so by astronomy, via megalithic triangulation pillars as permanent markers and by the mathematics of trigonometry, which would have been "by calculation" and not by ley lines, which would otherwise have required "direct measurement" of the lines.
In Stars, Stones and Scholars I analyzed how an ancient astronomy-based land survey system could be reconstructed via the most ancient megaliths and megalithic sites.
My book had nothing to do with "leylines" and never mentions the term in the plural, only referring to two alignments, one of which, as I wrote, was "the famous "linear" ley line (leyline) site of Mên-an-Tol" (not my naming), which I equated astronomically with the thread of the needle at the Cord of the Fish in ca. 3000 B.C.:
Traditional "Ley Lines", if they actually existed in ancient days, are a completely different animal than Menantol, and alleged by their proponents to relate to ancient trade routes, etc. and not to formations such as above. That this group of megaliths is seen as a ley line by some is not my creation. This did not keep the anonymous bad archaeologists at the blog "Bad Archaeology" from libeling my person and alleging erroneously that I "accepted" ley lines, which I do not. See that story here.
In the English-speaking world Alfred Watkins is sometimes considered to be the father of the "leyline hunters" and I did a page about him quite number of years ago at lexiline.com.
A colleague recently made me aware of similar theories presented for France about the same time as Watkins by Xavier Guichard (that link goes to a detailed article), whose biography at the Wikipedia reads in short:
"Xavier Guichard (1870 – 1947) was a French Director of Police, archaeologist and writer.I hold the label "sacred geometry" to be inappropriate because it smacks of esoterism and begs the question in its name, i.e. it already makes a value judgment about the nature of things whose proof still awaits us. First prove that such lines existed, THEN prove that they were "sacred", which I doubt, because IF such lines existed, they initially served practical rather than religious purposes.
Xavier Guichard appears in the novels of Georges Simenon as the superior of Jules Maigret.
His 1936 work Eleusis Alesia. Enquête sur les origines de la civilisation européenne is an early example of research into sacred geometry."
Alex Whitaker at his site "Ancient-Wisdom" writes about this practical purpose as follows:
Could such ancient paths of trade have existed?"Similarly to Guichard (above), Watkins believed that the lines were associated with former 'Trade routes' for important commodities such as water and salt. He found confirmation in this through 'name-associated' leys. Even today the Bedouins of North Africa use the line system marked out by standing stones and cairns to help them traverse the deserts. A letter to the Observer (5 Jan 1930), notes similarities with Watkins theories and the local natives of Ceylon, who had to travel long distances to the salt pans. The tracks were always straight through the forest, were sighted on some distant hill, (called 'salt-hill'), and that the way was marked at intervals by large stones (called 'salt-stones'), similar to those in Britain. On the other hand, should the leys be ancient tracks then it should be possible to see one point from another. Also it is noted that there are many ancient 'tracks' across Britain, such as the Ridgeway, and none of them are dead straight."
Yes, of course. But they need not be ley lines.
Indeed, in my book, Stars, Stones and Scholars, I allege that the oldest remnants of the Great Wall of China follow the route of the extended Ancient Silk Road and that the landmarks used by travelers on that road were astronomical. The path of the stars, as it were, was duplicated on Earth as a road map. North of the Great Wall of China there is often nothing but vast expanses of empty, desolate territory, so that the original wall was hardly needed to protect against invading hordes. Rather, it was a main road, mapped by the heavens, later fortified. Simple enough.
There may be some overlap of ley lines with megalithic research, as in the case of the standing stones and cairns used by the Bedouins, but these are not the locations that I focus on in my work.
What I do is to examine known megalithic sites -- especially those involving gigantic multiple megalithic standing stones -- from the standpoint of ancient land survey by astronomy.