A simple mound in the ground? Not to the expert eye of my walking compnaion. This, he said, is clearly the site of an old moated house from medieval times.
Being a bit of a sceptic, I had to check when we got back. He was right: the house, near Hilderstone, was probably part of the possessions of the Malbanks, a family who acquired a lot of land in England thanks to their loyalty to William The Conqueror in supporting his wars against the Anglo-Saxons (and Welsh).
I shall take mounds more seriously in future.