Wandlebury Hill Fort

[3] There are at least two theories regarding why the Wandlebury Hill Fort was built on this site: it may have been chosen because of its tactical grounds, or because it would be the last fortress in a line which controlled the Thames-Stort-Cam Valley route.

[3] The first hillfort was constructed in about 400 BC, consisting of "a substantial outer ditch and an inner rampart bank of chalk rubble and soil, enclosing a circular area of about 6 ha.

The study by C. A. E. O'Brien was an attempt to prove that Wandlebury Ring was far older than previously thought and that the hill fort was built on an existing structure.

O'Brien provided evidence that Wandlebury Ring was an astronomical structure (perhaps a huge calendar) similar to Stonehenge and Avebury stone circle, and was possibly engineered by the same team of mathematicians/astronomers.

O'Brien also reported evidence of a loxodrome (a line following the angle of the Earth), marked with monoliths, running from Wandlebury Ring to the earthworks at Hatfield Forest.

Gervase of Tilbury said in his Otia Imperialia of 1214:[9] In England, on the borders of the diocese of Ely, there is a town called Cantabrica, just outside of which is a place known as Wandlebria, from the fact that the Wandeli, when ravaging Britain and savagely putting to death the Christians, placed their camp there, Now, on the hill-top where they pitched their tents, is a level space ringed by entrenchments with a single point of entry, like a gate.