Some of the oldest highways in Britain, built over 5,000 years ago to guide Bronze Age man across the treacherous wetlands of the Somerset Levels, have been completely destroyed by modern agriculture. The scientists, who carried out the first systematic survey to assess the scale of the damage, described their findings as "quite shocking, but not unexpected."
     They opened small trenches to check sites which, excavated over the last century, once held startlingly well preserved organic remains. This time the scientists found that as the land has been drained, almost all the sites have been seriously damaged, and many destroyed. Two Neolithic trackways, The Abbot's Way and Bell Track (3000-2500 BCE), were only 40cm from the present ground surface meaning they were always above the water level. Those two trackways have disintegrated completely, leaving only smears of dust in the soil and the odd scrap of pottery and flint. At three other sites, including a late Bronze Age structure possibly used for rituals, the water table dipped below the wooden remains for between three and five months during the summer. Two of those sites have probably been destroyed, since the scientists failed to locate them - even though they were in pasture land, generally regarded as far less damaging to archaeology than tillage.
     They found the Iron Age lake village at Meare so damaged "that the only remaining organic components were shrivelled and contorted wood fragments". Waterlogged peat is 90% water, and originally preserved the stakes, wicker frames and plank surfaces of a network of tracks across the bogs, and of fish traps and village sites. Many are now permanently above the water level, even in wet winters: as the soil dries out, the ancient wood simply disintegrates.
     The only sites which remain in good condition are part of the Sweet Track, a main road built around 5,800 years ago, in a nature reserve where the original water level is maintained, and the Glastonbury Lake Village which is owned by a trust: the suggestion is that if both were on privately owned farmland they too might have been destroyed.
     The survey was jointly carried out by English Heritage, the Environment Agency and Somerset County Council. The only hope to preserve those ancient relics lies in persuading farmers to join agricultural stewardship schemes, which compensate for a return to traditional low impact agricultural methods. Richard Brunning, of Somerset County Council Heritage Service said: "It was a shock to see the damage that desiccation has caused. At least we now know."

Sources: BBC News, The Guardian (7 October 2005)