One of the most complex and enigmatic agriglyphs I've seen is the one from Barbury Castle, July 17 1991. Some have seen it as a three-dimensional figure rendered in the two-dimensional (flat) field. I see this too. Upon studying it, I think I know what it symbolizes. At least, I've found meaning in it for me. The balance of the thing was already esthetically pleasing.

It appears that the triangular shape is actually a three-sided pyramid. The triangle is arguably the most stable of figures and so a fully dimensional one would be even stronger.

IF this is a 3-sided pyramid, then there are four points or corners. At each of these is a symbol: open circle, stepped-spiral, pinwheel circle and a solid circle (in the 'back', currently appearing through the center of two rings.)
Now if we knock out the two rings for a minute, we can see the four elements at the points. I literally mean Elements. I would take the empty circle to mean Air. The pinwheel might be seen as the swirls or waves of Water. The jagged spiral perhaps as Fire. That would leave the solid circle to mean Earth. It appears smaller than the other three, and appropriately so, because IF this is a 3Dim figure, the solid circle is farther away and would be seen smaller as a result. This is in fact a major hint that the triangle is a 3-sided pyramid.

So, I see Earth, Air, Fire and Water as the cornerstones of the 3-sided pyramid. And what are the concentric circles? For me, they are the radiating energy of Spirit, the fifth element, which infuses all, being the force of Life.

I've seen a few discussions on this formation. I don't think I've read anything about this interpretation. I am not at all concerned with whether I am 'right' about it. The nature of these things may be intended to be gleaned with individual meaning, however, I rather thought that what I saw in this one was pretty significant. :) After all... what's more important here on this planet than the four elements and spirit with them?