THE hot dry weather is revealing some of Oxfordshire’s Bronze Age history normally hidden from view.

Hot air balloon pilot Michael Wolf, of Reading Road, Wallingford, was training another pilot near North Stoke when they spotted several dark circles in a farmer’s field.

Crops had grown at different speeds because of ancient ditches hidden beneath the soil which once surrounded prehistoric burial mounds.

The site dates back 3,500 years but is hidden under fields and normally cannot be seen.

The 52-year-old said: “In twelve years of ballooning, I have never seen anything as clear as this. It was like looking down on a map.

“I have flown over this field before, and never seen any marks. The hot weather must have created absolutely perfect conditions for seeing the marks.”

He added: “There were seven or eight big circles. It was absolutely fantastic.”

County archaeologist Paul Smith said: “There are very extensive areas of Bronze Age barrow cemeteries in that area, and some Roman remains too. There is a whole mix of multi-period sites.

“There has not been a lot of excavation, but these sites periodically show up through crops.

“When it has been dry, the ditches once dug for round barrows hold more moisture than the surrounding area, and when the rest of the field is ripening, the crops above the ditch are considerably greener.

He added: “This period of the summer is the best time to see crop marks, but it may last for just a few days or a few weeks.

“Some summers are definitely better than others. This year, a lot of sites are showing up.”

He said the county council’s archaeology service had been contacted by a number of people who had spotted other marks across the county, either from planes and hot air balloons, or while passing through the countryside on trains or buses.

The barrows, constructed between 2,200 BC and 1,000 BC, would once have been mounds, like the prehistoric Seven Barrows site on the Lambourn Downs south of Wantage, but over the centuries, farming has obliterated all surface traces of them.