AVEBURY, England -- Terence Meaden arrived late and breathless, his plans muddled and his glasses askew, having forgotten the time of our appointment and having neglected to bring my cellphone number.

He had come to show us the prehistoric stones and barrows of Avebury, but, with his deep knowledge and absent-minded charm, he seemed the model of modern British eccentricity.

He cast a worried eye toward the weather. The sun was shining --- a fairly rare event in winter --- but clouds were looming. Certain rock formations were best viewed in sunlight, he said. In anticipation of afternoon gloom, we would have to forgo his usual chronological tour and work with the elements.

But where to start, where to start?

When most people consider prehistoric sites in Britain, their thoughts turn to Stonehenge, the circle of stone megaliths so massive it boggles the mind to imagine how ancient people could have moved them into place, let alone calculated how to align them with the summer solstice.

But there is more here than just Stonehenge. Scientists know of hundreds of henges --- circular enclosures surrounded by banks and ditches --- in Britain.

And one of the most impressive is Avebury. Less than 18 miles north of Stonehenge, Avebury is a much larger and more extensive site. With barrows, a long, stone-lined "avenue" and a henge 1,140 feet in diameter that surrounds two smaller stone circles, Avebury offers archaeologists many more clues to interpret and puzzles to ponder.

Avebury may not be as famous as Stonehenge but is not unknown to tourists. Many wander among the stones, some weighing 60 tons, that cut right through the small village. They just park their cars, get out and walk among the relics.

So, I asked, do many visitors browse their way through the megaliths without the faintest idea of the significance of what they are seeing?

Meaden pondered the question as if he were stunned.

"That," he finally exclaimed, "is certain."

It had been precisely to avoid that sort of blissful but ignorant experience that my brother-in-law and I hired Meaden. A retired physics professor-turned archaeologist, Meaden, who is 66, has studied Avebury seriously for 15 years. He is the author of one book on Stonehenge and another called "The Secrets of the Avebury Stones: Britain's Greatest Megalithic Temple."

In addition to the stone circles and mile-and-a-half avenue, the sites include the West Kennet Long Barrow, a burial site that was built around 3700 B.C. and remained in use for 1,000 years. It is one of the largest prehistoric tombs in England --- almost 200 yards long --- and is aligned so that, at each of the two equinoxes, the sun shines right down the center of it.

"These people 5,000 years ago were not dunces at all," Meaden said. "With the technologies they had, they were just as clever as us."

Skulls were found in the barrow when it was excavated. Even today, people enter the barrow and leave candles or flowers.

It is a site for meditation. The spiritual among us reflect on the long chain of human life and, perhaps, the meaning of death. The archaeologists among us reflect on what kind of life was lived by people who were sophisticated enough to mark the solstice but who left no written record.

"To some extent, the monuments can speak to us," Meaden said. "Certainly everything went up with a meaning and a purpose."

Without any written history, these ruins are, to some extent, a Rorschach test. So little is known for certain. Archaeologists cannot even agree on whether the circles that abound in England --- some made of stone, others of timber --- were roofed structures or open sundials.

Meaden is clear about what he sees. When he looks at a cleft in a rock, he sees vulva. The stones were set here, he believes, by a goddess-worshipping society. And the great circle at Avebury was a temple build to glorify a Neolithic earth goddess.

It is a theory he addressed with great vigor in his book on Avebury. But in person, he sidled up to the topic more cautiously, assessing his audience.

Outside the West Kennet Long Barrow, he said there was "a general belief in a mother earth goddess --- a mother earth figure --- as the leading figure in their system of belief."

Other unrelated societies around the world came up with similar ideas, he noted. Burial in the earthen barrow, he said, was a return to the womb.

A pause.

"The gallery," he continued, referring to the first chamber of the barrow, "then corresponds to the vagina."

When, for whatever reason, the ancient people stopped using the barrow, they put a great stone in front of the opening. "This is a blocking stone," Meaden said, "and it has a carved vulva in it."

This is a difficult claim for the uninitiated to evaluate. The crease might be nothing more than a watermark in the stone. On the other hand, there was a certain resemblance.

The theory is plausible. And once one accepts this idea, Meaden said, a great deal about the Avebury stones is explained.

The stone circle was a calendar in which, as the months went by, the central phallic stone cast its shadow on the feminine stones at the perimeter to mark important dates in the agricultural year.

But a compelling aspect of archaeology is that the truth ultimately can never be known. New finds will continue, current theories will have to be revised and there will always be room for new ones. Carbon dating gives us new evidence and science continues to advance. But archaeological discoveries can be made by anyone.

As he walked from site to site, wearing his Wellingtons against the thick British mud, Meaden kept his eyes on the ground and urged us to do the same. The earth is disgorging some prehistoric treasures as fast as it swallows others.

"Moles are doing the archaeology for us," he said, stooping to pick up a bluish chip. "You might find a piece of flint that someone held in his hand 7,000 years ago."

He turned the flint chip over in his hand to see whether both sides of the stone had been worked. They had.

"That was a tool," he exclaimed. Satisfied, he put it in his pocket to take home.

"I like making the point that all of us can do a wee bit of archaeology," he said.

IF YOU GO

Avebury, about 80 miles west of London, is an easy day trip. To get there, take the M4 highway west from London; at Exit 15, go south on the A346; at Marlborough, go west on the A4, and at Beckhampton, go north on the A361 to Avebury.

Two forms of public transportation will get you to Avebury. You can take a train from Paddington Station in London to Swindon; at Swindon, walk, following the signs, to the Swindon Bus Garage, then take the bus to Avebury. Or a National Express Coach bus, from Victoria Station in London to the Swindon Bus Garage. The trip should take less than two hours each way. Prices vary according to the time of day and the day of the week.

To contact Terence Meaden, e-mail terence.meaden@stonehenge-avebury.net.