An archaeologist in Australia has discovered hundreds of mysterious stone structures atop lava domes in Saudi Arabia.

By way of Google Earth images, professor David Kennedy was able to find  an astounding 400 of the enigmatic anomalies which he believes could be  up to 9,000 years old.

The strange structures differ vastly in size with the smallest being 43  feet long compared to the biggest which is a whopping 1,699 feet long.

Known as 'gates' due to how they appear from above, the purpose of the stone sites remains a mystery to researchers.

More on this remarkable story at the Coast to Coast AM website.