Line A - Cam Valley Loxodrome

Made up of standing stones and other markers placed one megalithic mile apart for 26 megalithic miles from Hatfield Forest in Essex to Wandlebury Ring on the Gog Magog Hills South of Cambridge

Constructed c. 2,500 BC to allow astronomical observations to be made for the purposes of time determination, and most of the positional observations made visually - both of fundamental importance to what is now called Meridian Astronomy