Rocks of ages: how Hadrian's legacy lives on

What once kept out hordes of bloodthirsty warriors is, nearly 2,000 years later, barely proof against the most timid of sheep. But if Hadrian's Wall is now low on stature, it remains high on atmosphere, finds Harry Pearson

- Harry Pearson

TO look north-eastwards from Walltown Crags in Northumberland is to gaze upon an English wilderness. The ashen cliffs of the Whin Sill drop 75ft to a brindle-colored plain that stretches far into the distance, its surface is broken by patches of dark heather and the occasional glistening black splash of groundwater. What few trees survive are small and stunted, hunchbacked against a prevailing westerly wind that rattles the bent grass and sends crows somersaulting across the vast grey sky. The cawing corvine protests are the only sound of life. To stand here on a swirling day in winter (and winter goes on for a long time here) is to feel as our ancestors must have done: tiny in a big world. The Romans who arrived here in the first century looked at it and felt they had reached the lip of civilisation. They called the place Ad Fines-the End of the Earth.

Yet, despite that, the Romans came there in their tens of thousands and stayed for close to 300 years. Face east or west from Walltown and you look along their great legacy, a knobbly line of immaculate masonry that runs fastidiously along the cliff edge: Hadrian's Wall.

This breathtaking piece of engineering was begun 1,900 years ago, in AD122. It would stretch across the narrowest point in Britain, 73 miles from the mouth of the River Tyne to the Solway Firth, stand 15ft high and 10ft across, incorporate 16 forts, 80 mile castles, and 240 watchtowers, as well as dozens of bridges, and be flanked by ditches and earthworks.