ALONG THE RIDGE of chalk hills on England's southeast coast runs a grassy track that has served as a footpath from time beyond memory.
For 80 miles the South Downs Way clings like a faded ribbon to moors and meadows dotted with ancient burial mounds. It winds through a rolling upland cropped close by sheep and furrowed by the plow.
At Rodmell, the path drops to the Valley of the Ouse and Virginia Woolf's erstwhile haunts. Near South Harting in the west it skirts that handsome old manor house, Uppark, where H.G. Wells, the son of a servant, wrote his first stories.
The ridgeway track ranges deep into Sussex from the Hampshire border to Eastbourne on the English Channel. To hike its length takes the better part of a week.
Far less arduous is a long afternoon's outing that covers an 11-mile stretch of the track between a pair of mossy Sussex villages -- Cocking, with its 14th century church, and Houghton, washed by the languid River Arun.
Just 50 miles from London, the trek traverses some of the most glorious countryside in Britain, and, except at scattered road crossings, it is the picture of rural tranquility undisturbed by motor traffic. All a visitor needs is a decent pair of walking shoes and a healthy amount of stamina.
The Cocking section of the walk begins half a mile from the village, where the South Downs Way intersects the Chichester-Midhurst road (A-286) 8 1/2 miles north of Chichester. A wooden signpost points to the path, straggling up the smooth, steep flank of Manorfarm Down.
Hikers have a hard slog to the 500-foot summit. There the track levels off. It tunnels through a three-mile wood of fir and beech, then emerges in the clear Littleton Down.
Ahead, the path seems to peter out in a cow pasture but is quickly picked up as a faint thread falling diagonally to the busy Chich ester-Petworth road (A-285). On the other side, the path cuts a broad gap between earthen banks; wayfarers soon put the din of cars behind them.
The track climbs steadily to the crest of Sutton Down through wheat fields edged with purple thistle and cottony tufts of old man's beard. Here the loveliest of all chalk-land flowers, the scabious, raises its delicately rounded lavender head.
A magnificent stretch of country follows. A little more than a mile of exhilarating walking leads to the western spur of Bignor Hill. In the south, the downs -- the word derives from the Old English "dun," meaning hill -- shelve to a patchwork tapestry of lowland farms pierced by the far-off spire of Chichester Cathedral. Beyond is the metallic glint of the sea.
The path dips gently eastward. Studded with flints, it bears left along a raised remnant of the original Stane Street. This was the laser-straight, stone-paved road that Roman conquerors built to link first-century Chichester, then called Noviomagus, with London, or Londinium.
After a few hundred yards walkers turn right across a cattle grid where the path, still clearly signposted, eases up a chalk-stippled field to Bignor Hill's 727-foot crown.
All of down land spreads out in the east. As far as the eye can see, the surging rampart of turf-mantled chalk curls to the wide horizon like a long, low wave about to break.
Northward, the downs form an escarpment that drops abruptly to a sweeping plain speckled with storybook villages of thatch and flint: Sutton and Barlavington close by, the red roofs of distant Petworth huddled around a stately mansion of honey-colored stone.
On these heights grazing sheep, pecking pheasants and an occasional fellow hiker or horse rider are the wayfarer's only companions. The sky invariably is filled with sailing clouds. Sunlight and shadow chase each other across the folding hills. The view is breathtaking.
From Bignor Hill walkers trot down a steepish incline to the base of Westburton Hill. Here, at three corrugated metal barns, the path splits. The left branch detours west a mile to the remains of a Roman farm villa unearthed at Bignor (the mosaics alone are worth a visit); the right continues east along the South Downs Way.
The chalky track wanders high across open fields. Beyond the A-19 road the line of the way can be seen drifting down to a vivid green flood plain creased by the River Arun.
For weary day trekkers the end comes at nearby Houghton, a comely hamlet graced by an agreeably antiquated pub, the George & Dragon. This is where King Charles II is reputed to have stopped in 1651, so a plaque tells us, "to take ale."
As in Charles' time, the George is just the spot to savor a malty pint against the splendid backdrop of Sussex Downs. It provides a welcome respite from the dust of the trail and a satisfying cap to a memorable day.
If you go: Chichester is a good base for exploring the nearby downs. The cathedral town is an hour and 45 minute train ride from London. Drivers should follow the M-4 and M-25 Motorways to Routes A-3 and A-286.
The weather is changeable on the downs; a sweater and raincoat are musts. Ordnance Survey map 197 and the larger scale SU8 1/9 1 -- both covering the Cocking-Houghton section of the way -- can be obtained in Chichester in any bookstore or in London at Stanfords International Map Center, 12-14 Long Acre. An excellent 76-page guide, "Along the South Downs Way," also is available in Chichester bookstores.
For more information: The British Tourist Authority (40 W. 57th St., New York, N.Y. 10019) has specifics about hotels, restaurants and walking and touring in and around Chichester. For trekking elsewhere in England, Scotland and Wales, ask for a free copy of the "Walking in Britain" brochure.