The Big Circles are a collection of 12 giant circular stone structures spread across parts of Jordan and Syria.
For reasons unknown, Rees findings were ignored and promptly forgotten.
It took another 60 years before anyone noticed them again.
They are nearly circular, ranging from 720 feet to over 1,200 feet across.
The circles originally contained no openings, although over the centuries some of the walls have crumbled.
But why they were built is a mystery.
Besides, there is no reason for animal pens to have a precise shape.
A more recent Big Circle was spotted in Syria.
