A bowl barrow in the garden of a very posh house, I took my photo very quickly in case they called the police! The barrow is 25 metres in diameter and 2 metres in height. Apparently it has an intact ditch, I couldn't see it as the plant cover was too dense.
This and the similar Ralph's barrow a few hundred metres to the east are lucky survivals in the middle of a housing estate. These barrows are part of a strung out cemetery on the former Parley heath, of which only a small part remains.
The street is very helpfully named after the monument.