An aerial shot of the moorland shows the extent of the fire damage - marked by the dark patches at top left. Picture courtesy English Heritage.

Archaeologists are pondering one of the most intriguing archaeological discoveries for some years after a fire revealed a unique carved stone thought to be 4,000 years old.

The find came to light after a blaze in 2003 at Fylingdales near Whitby consumed two and a half square kilometres of heather moorland - before being brought under control by hundreds of fire fighters and a water-dumping helicopter.

However, in the fire’s aftermath archaeologists were astonished to find a vast array of archaeological remains – uncovered by the intensity of the blaze, which burnt away much of the peat.

“The fire had a devastating impact, but it also revealed an astonishing archaeological landscape,” said Neil Redfern, English Heritage Inspector of Ancient Monuments.

“When we stepped over the scorched terrain and reviewed aerial photographs, we were confronted by a vast number of features we had no idea existed before. To find such well preserved signs of settlement and human activity over such a long period in such a small area is amazing.”

The carved rock is believed to be unique in England. Picture courtesy English Heritage

The area yielded Mesolithic flints, 185 carved rocks (three times the previous recorded number), old trackways and evidence of the 17th century alum industry. There were even slit trenches from the last war.

But of the many finds the most interesting and significant is the carved stone – adorned with a carved zigzag design around a central feature, which resembles an angular hour-glass.

Archaeologists believe the stone to be unique among examples of late Neolithic/Bronze Age rock art, which is usually dominated by curvilinear cup and ring marks. Instead, the designs on the stone recall those found on materials such as beaker pottery – opening up a wealth of interpretive possibilities.

"We laser scanned the stone so we could rotate it and look at it from different angles," explained Mr Redfern. "We're now thinking the stone is possibly some kind of map - the laser technology means we can see a landscape with mountains and sky."

The task of understanding and interpreting is ongoing although Mr Redfern admits that experts have few clues to go on.

"The great thing is that with an image like this you can come up with all sorts of theories," he explained. "With rock art there aren't that many people that really know - so we can all enjoy the experience of working out what it actually means."

The devastating wildfire left large tracts of moorland scorched and blackened. Picture courtesy English Heritage.

The stone, although examined, photographed and laser scanned, was left in situ in the ground along with many of the found items. The unusual step of leaving it in place is part of an ambitious project to restore the rich ecology of the moor, which is part of a designated Site of Special Scientific Interest (SSSI).

"I would say: 'why do you need artefacts to go into a museum?' Someone put it there in the past, so who am I to remove it? To me it's not an artefact if it's removed from its context - it's part of that landscape," added Mr Redfern.

The restoration of the moorland has been facilitated by a £200,000 grant from Defra, under a Countryside Stewardship Scheme Special Project. As well as restoring the moor’s dynamic range of habitats for wildlife and plants, the re-vegetation is also intended to protect the archaeology beneath the ground by preventing erosion.

Mr Redfern believes this innovative approach will prevent the rich archaeology of the area being destroyed. “The success of this approach is clear to see on the ground and will serve as a template for how agencies and landowners handle similar disasters elsewhere in the country,” he added.