It says Pete G made the discovery, there's two pictures, one from the air. It says it's not definite until it's examined properly but if it's real then it's one of the most 'remarkable discoveries by an ameteur prehistorian in recent years'. It says if it's a natural mound, it could have been the inspiration for Silbury.
It also says some have said it could be a windmill base or Victorian folly. So they're saying "a very interesting find, but no firm facts as yet".
It gives a link to Pete's site too. All good stuff I reckon!