Stone 98 was one of the two enormous stones guarding the southern entrance to Avebury stone circle. In the neolithic if you had approached Avebury from the south you would have passed through this massive stone portal, and if you had glanced right as you did so you would have seen this enormous giant inspecting you!
As has already been explained, there is a huge controversy about whether the faces at Avebury are mere Rorschach effects arising accidentally from the minds interpretation of randomly shaped sarsen stones, or whether our ancestors creatively selected stones that naturally reminded them of characters from their folklore and then deliberately and minimally sculpted them to create the weird effects we see today.
Looking at this image of stone 98 I am very suspicious about the shape of the "eye socket". Is that really a shape that might have been naturally carved by the sea, or did people gouge out an eye deliberately, perhaps hammering away with round stone mauls like the ones used at nearby Stonehenge?
Image copyright David Baldwin Night Photography