Pyon Wood Camp is a scheduled monument described in the catalogue as a small multivallate Iron Age hill fort. What it looked like was a round hill covered in trees. When I looked up the meaning of the word multivallate I found it meant a hill fort with three or more rings of concentric defences. Since the easiest way to start an argument amongst archaeologists is to ask them what purpose hill forts actually served – as defended villages, refuges of last resorts, ritual centres, palaces of tribal chiefs, cattle herding stations – none of that information was particularly useful.

Neither was Beverley Brook.

‘More Silurian limestone,’ she said. ‘Topped by the usual suspects – oak and ash, some beech, a couple of birch.’

It was particularly hot that morning. Victor had complained that the recent hot weather was buggering up his harvesting schedule, but he hoped that some of the rain they’d had in Wales would shift over his way.

‘Not that I want a thunderstorm,’ he’d said. ‘But a shower or two to take the edge off would be nice.’

It was too hot to walk up the shimmering track from the Roman road, so I risked the low slung underside of the Asbo and drove uphill until we reached the spot, plus or minus twenty metres or so, where the Antiquarian map said that the trail into the monument should start. It wasn’t exactly well signposted, and if there was a stile or other public access, me and Beverley must have missed it. In the end we climbed over a fence and slogged through some dense bracken until we reached a close approximation of a path that wound around the hill.

It was close under the shade of the trees and not notably cooler. The air was heavy with a sickly sweet smell that Beverley said was probably the rhododendrons, and the scent of scorched bark and resin that I’d started to think of as overheated forest. Something hooted further up the hill.

‘Wood pigeon,’ said Beverley.

‘I’ve heard that in London,’ I said.

‘Yes,’ said Beverley slowly, ‘we have birds in London. Many of them of the same species.’

Amongst the trees and undergrowth, the ditches and ramparts were hard to distinguish from the steep slope of the hill. It was only when the trail rounded the north-east corner and we found the entrance that I realised the ramparts, despite obvious damage, were twice my height. We laboured up onto what I supposed must have been the central enclosure, although I couldn’t see it for the trees. And, despite the heat, we decided to follow the path to its bitter end. Drifts of foxglove started to appear amongst the bracken and bramble, growing more frequent until we stepped out into a glade awash with purple. The clearing was almost too circular to be natural, and certainly large enough that it ought to have shown up on Google Earth.