It's pouring at Camelot. One hundred miles and 1,500 years west of London, three men in muddy boots are sitting on a grassy ledge at the hilltop remains of South Cadbury Castle. Below, the rain-dirty fields of southwest England stretch in every direction; miles above, so do the black clouds. So why are members of a British walking club sitting up here getting drenched?

"We're intrepid ramblers!" the cynic, the leader of the group, replies dismissively from atop his muddy mound.

But if you step back a few feet, it becomes clear that that muddy mound is something else--a flat-topped rampart that coils around the massive hill, too deliberately level to be a natural formation. Someone clearly built it, someone who long ago raised timber halls here on this lonely hilltop plateau and called it home.

For centuries, the romantic and hopeful have called it something else: Camelot.

King Arthur is buried nearby, some say, near Glastonbury, site of the mythical "Isle of Avalon." And farther west, along the rugged coast of Cornwall, you'll find his birthplace, a windy ruin high above an unreachable cave near a town called Tintagel. But any journey through King Arthur's England begins here, at South Cadbury. Even the cynic knows this; it's why he and his colleagues are here on a rainy day. Press him and he'll admit it.

"Of course," he finally says, a bit sheepishly, as he squints into the mist, "there's the legend . . ."

South Cadbury is a "castle" only by an extremely generous definition of the word. Surrounded by a small village, this 500-foot hill offers no dramatic towers or majestic ruins--it's far too old for that, since it predates the age of the brick-and-mortar things we think of as "castles." But the past rises to meet you on the flat earthen ramparts; they encircle the hill's suspiciously open top and defend its steep sides. Look down as you walk the perimeter, through a moat of green leaves, and you can see the lower earthen fortifications--solid, thick, deliberate.

South Cadbury has long been associated with King Arthur. Sixteenth-century antiquarian John Leland reported that locals knew the place as "Camalat" and believed that Arthur and his knights slept inside the hill. At the right time of year, they said, you could see Arthur sleeping--or if you were fortunate, you could even hear his knights ride out of the hill. In the 1960s, archaeologists digging at South Cadbury harnessed the allure of local folklore under the auspices of the Camelot Research Committee--a name that gave legends new credibility in the minds of the British public.

Today the site may not evoke fairy-tale images of knights in shining armor, but South Cadbury does manage to muster the vanished realities of an ancient hill-fort: a flurry of armed activity beneath darkening skies, a warlord shouting orders to his men as they prepare to defend against invading tribes--all in vain. Those tribes would eventually overrun much of Britain, bringing with them a new culture and a new language: English. That's dramatic enough in its way.

For thousands of years, Britons of various persuasions lived at South Cadbury, from Neolithic settlers to Anglo-Saxon kings. It's easy to see why; any bloodthirsty attacker would be exhausted by the time he slogged his way over the hill's steep defenses. But it's one specific generation of residents that inspires the Camelot connection. Around A.D. 500, someone built those fortified ramparts using a combination of stone, timber and rubble--a typically Celtic method of construction. They used bits and pieces of Roman-style masonry and a Roman-style gatehouse.

Conveniently, in the right place at the right time was just such a fellow, leading both the Celts and the Romans against invading Germanic tribes.

Chroniclers call him Arthur.

"If King Arthur didn't live, he should have," wrote Winston Churchill with characteristic stubbornness.

Unfortunately, Arthur is suspiciously scarce in actual British history. The Annales Cambriae (Annals of Wales), a Welsh chronicle written around A.D. 950, lists battles fought by an Arthur in A.D. 516 and 537, that second entry teasingly referring to "the Battle of Camlann, in which Arthur and Medraut fell." The Historia Brittonum, usually attributed to a 9th-century Welsh monk named Nennius, lists 12 battles of Arthur--not yet a king, but a dux bellorum, "leader of wars," fighting alongside the kings of Britain against Germanic invaders. In 1125, William of Malmesbury asserted the existence of "the warlike Arthur," a figure "not to be dreamed of in false myths, but proclaimed in truthful histories." The problem is, he was writing about 600 years too late.

A 12th-century bishop named Geoffrey of Monmouth, hard at work on political propaganda for his Norman patrons, appropriated Guinevere and the prophet Merlin from Welsh tales and interwove them into imaginative fables of Arthur conquering half the world. The French would add Camelot and Lancelot, and the Arthurian legend was complete--and a far cry indeed from its sparse historical origins.

Madeline, visiting from New Zealand, has just come to Glastonbury, the second site on the Arthurian tour, from an astrology conference in Dorset. "I climbed the Tor yesterday," she says over breakfast, "and I could just feel the masculine energy. Couldn't you?"

Three hours west of London, the village of Glastonbury is at the base of another hill, this one high and green and topped with a medieval tower. The 500-foot Tor--from a Celtic word meaning "hill"--was once surrounded by fetid marshes and known as Ynis Witrin, "the Isle of Glass." The Tor was sacred to the Celts, who may have considered it hollow, a mystical place of the dead or an entrance to other worlds. The lone tower looks as if it's always been there, but in fact it's all that remains of a church that crumbled after a rare English earthquake.

The view from the top of the hill is worth the hike; the village streets and the vast ruins of Glastonbury Abbey sit quietly at the foot of the Tor. Eleven miles to the southeast, across the patchwork landscape that poet and Arthurian devotee William Morris called "the deep still land of colors," South Cadbury Castle stands purposefully on the horizon.

Locals know what they have here. It may not be surrounded by water any longer, but in Glastonbury, few have any doubts: The Tor is the Isle of Avalon.

Halfway up the Tor, a girl collapses wearily on a rock, questioning her parents' choice of family holiday with a rolling of her eyes and a frustrated glance at the tower above.

"Come on," pleads her smiling mother, bounding enthusiastically up the path, "we have to do our yoga exercises on top!"

She isn't being irreverent; Glastonbury's association with the spiritual in all its various forms is ancient and virtually unbroken. According to local legends, Joseph of Arimathea came to Glastonbury. Some say he brought the boy Jesus here; others claim that he founded the first Christian church in England. The Holy Thorn, a twisted tree that grows on the abbey grounds, is supposedly a remnant of the blooming staff that Joseph planted on nearby Wearyall Hill, and the mineral-rich waters of the Chalice Well, in a charming garden at the base of the Tor, are said by some to be aided by Joseph's other gift to Glastonbury, buried deep below the well: the Holy Grail. King Arthur supposedly came to Avalon for healing; today, people visit the Chalice Well to do the same, while seeking more diverse forms of spiritual treatment from Glastonbury's thriving New Age community.

The Holy Grail isn't Glastonbury's only Arthurian connection. In 1190, the monks at Glastonbury Abbey were digging a grave in their cemetery and unearthed a leaden cross with a surprising inscription: "Here lies the renowned King Arthur, buried in the island of Avalon." Digging deeper, 16 feet beneath a stone slab, the brothers found a hollow oak log containing two skeletons, one a large male who had suffered a brutal blow to the head, another a slighter female whose long blond hair crumbled when touched. With reverent haste, the monks reinterred the bones inside the abbey. Contemporaries had little doubt: The monks had found the tomb of Arthur and Guinevere.

The magnificent abbey was dissolved in 1539, stripped of its riches and allowed to fall into ruin. Today its remaining bits--a crumbling buttress here, a block of Gothic arches there--jut from the clipped, 36-acre lawn at the base of the Tor as if growing naturally. A sign near the altar marks Arthur's tomb, but there's no tomb there now, not even a floor, just a carpet of perfect green grass.

It's possible that the monks never really found Arthur's body. The English may have been trying to squelch rumors among the rebellious Welsh that one of their legendary heroes might someday return. It's also likely that the clever monks had thoroughly practical motives. Six years before the discovery of Arthur's grave, the abbey was devastated by fire, right around the time royal financial support for the abbey dried up. Discovering King Arthur's grave at the abbey's moment of greatest need would have been truly miraculous. Once word got out, the monks could have expected a steady stream of devout pilgrims--and, of course, their money.

But on a sunny day, within sight of the Tor, a short walk from the Chalice Well, standing in the grass near King Arthur's tomb in the ruins of an abbey, who wants to contemplate a monastic hoax?

"Yesterday, we went to the Abbey and stood on the spot where the altar used to be," Madeline explains, sipping tea, "to feel the power. Ley lines, you know--lines of power."

That lines of unnamed power could pass through the ruins of a medieval Christian cathedral in the shadow of a hill sacred to ancient pagans isn't even questioned in Glastonbury. On the village's High Street, a shop selling Eastern Orthodox icons coexists, with no apparent squabbles, alongside others selling crystals and aromatherapy supplies. The town also hosts an annual Goddess Conference while at the same time Catholic and Anglican clergy make regular summer pilgrimages to the Abbey ruins. One dubious theory even claims, with only the slimmest topological justification, that the Tor is the center of a giant earthen zodiac visible from the air.

Historically, Glastonbury has been whatever its residents, and its visitors, want it to be: England's pantheon, a disorienting center of traditional and not-so-traditional spirituality. It's also a place where myth and history intersect; King Arthur is right at home here.

Four hours west of Glastonbury, on the harsh northern coast of Cornwall, is Tintagel.

According to medieval storytellers, Merlin used his powers to help Uther Pendragon infiltrate the Duke of Cornwall's castle at Tintagel and seduce the duke's wife. In exchange for his magic, Merlin was allowed to raise the child conceived that night--the child who would become King Arthur. In his tamer Victorian version of the tale, Tennyson placed Merlin on the Tintagel coast, beholding numerous fiery waves, until a ninth wave, "gathering half the deep," deposited the infant Arthur on the shore. It's a mysterious tale, but Tennyson knew full well that mystery is the essence of the Arthurian legend.

In Cornwall, they've always felt more certain about the facts. Some early traditions place Arthur's court in Cornwall, not South Cadbury. In 1113, a group of French emissaries visiting nearby Bodmin were accosted by a raving man with a withered arm when they scoffed at the local belief that King Arthur was still alive. Arthur's Cornish heritage is the source of a certain amount of zealotry even today; some still say that the king fought his final battle in Cornwall, and that his sword Excalibur was thrown into nearby Dozmary Pool after his death. These dubious sites supposedly lie along the claustrophobic, twisting roads that lead to Tintagel, behind the impassible Cornish hedgerows and beyond the authority of most dutifully historic road maps.

The villagers at Tintagel may have embraced the legend a bit too strongly for some tastes, as the number of local businesses featuring "Arthur" and "Merlin" in their names attest. By day, Tintagel is just a small and unremarkable jumble of half a dozen little roads and a historic post office, just another tourist stop along the rugged Cornish coast. Arrive at night, however, and the imagination takes over. Cats rule over the deserted streets, and the sea can be heard--but not seen--wearing away the rocky shore. Walk though the blackness, past an eerie church graveyard along the coastal path, and you'll see . . . nothing. Tintagel at midnight is disquieting.

The alleged site of Arthur's birth is a short walk from town, along the tremendous rocky headland on the coast. Like a giant mossy boulder tossed into the sea, the Tintagel headland sits apart from the Cornish mainland, joined by a narrow causeway and a long, precarious staircase leading to the ruins of a medieval castle. The huge rocky surface of the headland demands exploration, but it's a surprisingly intimate place. Like Uther Pendragon before you, you may feel like a bit of an intruder.

The village is all but invisible, and the wind drowns out the sounds of Cornwall. Not even the presence of other tourists can dispel the loneliness of the site and the long-gone past evoked by the crumbling foundations. Paths lead around crags and over hillocks; on all sides, cliffs plummet into the sea. Wander off and you'll see why Tintagel inspired tales of enchantment. It's surprisingly easy to get lost, if only for a minute, on this vast, disorienting rock.

The castle walls date from the 12th century, 600 years too late for the historical Arthur. But bits of pottery from the 5th or 6th century hint at the true age of Tintagel and tantalized Arthur-seekers for years--until 1998, when archaeologists found a piece of 6th-century slate with a Latin inscription: "Artognou, father of a descendant of Coll, had this made." "Artognou" may sound only a little like "Arthur," but the public jumped to the obvious conclusions, much to the annoyance of sober historians. The need to find tangible proof of a legend is forgivably human--even if the ruins of southwest England do consign King Arthur more to myth than to history.

On the western side of Tintagel is a cave--Merlin's Cave--battered by the surf, barely reachable even at low tide. It's tempting to count the waves.

Jeff Sypeck last wrote for Travel about Portmeirion, Wales.

DETAILS: Arthur's England

GLASTONBURY: Glastonbury is about 100 miles west of London, about a three-hour drive on the A361, just off the A303. Buses make the run from Victoria Station each day for about $35 round trip.

South Cadbury Castle is about 11 miles southeast of Glastonbury near the Somerset-Dorset border, just off the A303. Follow signs for South Cadbury and proceed through the village to the car park. Although visitors are welcome, the grounds are private property and should be treated as such. Camping is not permitted.

The Chalice Well on Chilkwell Street (www.chalicewell.org.uk) is open year-round. Admission is about $3.20.

The ruins of Glastonbury Abbey (www.glastonburyabbey.com) are open daily except Christmas. Admission is about $5.

There are numerous B&Bs and guest houses in the village. Alison and Peter Brown of 12/13 Norbins Lane (telephone 011-44-1458-834650) offer comfortable, spacious rooms in their Victorian home just behind the High Street. Ann Madkins of Abbey Garth (5 Bere Lane, telephone 011-44-1458-832675) rents out two cozy spare rooms in her home just behind the Abbey grounds, providing that rarest of British amenities: accommodations for solo travelers. Many other guest houses and B&Bs, including those specializing in specific forms of meditation and "spiritual healing," can be found at the Glastonbury tourism Web site, www.glastonbury.co.uk, or at the "alternative" site, www.isleofavalon.co.uk.

TINTAGEL: Tintagel is about 200 miles west of London in Cornwall, about a seven-hour drive (from Glastonbury, it's about a four-hour drive along slow, twisting lanes). Best reached by car, the village is located on road B3263 between the towns of Camelford and Boscastle, by way of the M39 and off the M30, which connects Cornwall to the rest of England.

"King Arthur's Castle" (telephone 011-44-1840-770-328) is a short walk from the village along the coast. Admission is about $3.20.

Spartan but dramatic accommodations are available at the Tintagel Youth Hostel (telephone 011-44-1840-770-334), in a stunning nook on the cliffs overlooking the sea. Several affordable B&Bs and hotels are also available; consult the Cornwall Tourist Board's Web site, www.cornwall-online.co.uk, for more information.

INFORMATION: British Tourist Authority, 1-800-462-2748, www.visitbritain.com.

--Jeff Sypeck