The COG has a better photo, of course, but he has left the text to me. The Long Man of Wilmington is a chalk figure on the Downs in the lovely village of Wilmington. It may be prehistoric or it may be medieval 16th century or so, no one knows for sure. The earliest drawing of it dates to 1710. At that time it was just a depression in the grass, showing only in certain light or in a light snow. In the 19th century the local vicar outlined the shape with bricks, and more recently they have been replaced by concrete blocks. The vicar may have gotten the feet wrong, and he may have left off some details. Using archeological techniques, they've discovered that the head once had a helmeted shape and facial features. There is no evidence that it had genitalia like the other giant chalk figure, the Cern Abbas, there's also no evidence that it never had them.
Interestingly, there is some kind of nearly lost figure, which is revealed only by infrared photography, on Firle Beacon, the next hill over. That one, called The Firle Corn, is, logically, shaped like an ear of corn, but no one is sure what it's supposed to be. Off Topic but interesting, Firle Place, at the foot of Firle Beacon, was the ancestral home of General Gage, who lost the Battle of Bunker Hill.
As to the question of the age of the figure. Some work has shown that it was made in the 16th century, but there are some scholars who think it's much older. The whole hill, indeed, the whole area is riddled with prehistoric stuff. Just barely visible in the picture, above the figure at the crest of the hill you can see bumps that are various earthworks and tumuli. Just to the right of the figure, where the hill has kind of collapsed, there are the remains of a chalk pit and lime kiln with some funny terracing beneath it (see picture 2). And over to the left, not shown in the pictures, there's an old flint quarry.