Across much of the globe are ancient earthworks and stone monuments built for an unknown purpose. Their shared features suggest that they were originally part of a worldwide system, and John Michell argues that they served the elemental science of the archaic civilization that Plato referred to as Atlantis. In this connection the most significant modern discovery is that of "leys", the mysterious network of straight lines that link the ancient places of Britain and have their counterparts in China, Australia, South America, and elsewhere.

John Michell's studies of ancient measures have enabled him to define their exact values. The same units recur in the dimensions of monuments all over the world, from Stonehenge to Teotihuacan, and reveal the builders' knowledge of the size and shape of the spheroidal earth, and with it the outlines of their cosmology.