This is a reasonably well-preserved longbarrow: largely surrounded by firing ranges I suppose it only has burrowing animals to worry about. It’s unusual because it’s ovoid in shape, according to its EH record. It aligns NNE/SSW, with its broader end towards the sunrise, and sits on the false crest of a steep east-facing slope so as to impress people below. Another unusual feature is that it has a little round barrow right on its southern side, so close that it impinges on its ditch. Another small round barrow lies 100m to the north west.
(facts from Grinsell’s ‘Hampshire Barrows’)