ON THE GRASSY SLOPES of Rano Raraku, the great stone statues sleep, their sightless eyes blind to all that has happened since their journey to the sea was interrupted so very long ago.

Their world is gone: a world of simple beliefs and enormous tasks, of isolation and imagination, of a culture left alone to develop and devour in strange and untold ways.But the questions remain: How were these megaliths carved? How were they moved from quarries high on volcanic slopes to positions close to the sea? How were they erected? How and more intriguing why?

EASTER ISLAND, so named because it was on Easter Sunday in 1722 that it was discovered by the European world, is a tiny speck in the vast Pacific Ocean. Barely 45 square miles in size, hundreds of miles from any other land, the surprise is not that it took the Europeans so long to find it, but that it was found at all even by the earlier settlers.

A Dutchman named Jacob Roggeveen was the first of the Europeans. He found a few thousand impoverished natives, basically living off sparsely cultivated lands. And he found the statues.

"What the form of worship of these people comprises, we were not able to gather any full knowledge of, owing to the shortness

of our stay among them," he wrote. "We noticed only that they kindle fire in front of certain remarkable tall stone figures they set up; and thereafter squatting on their heels with heads bowed down, they bring the palms of their hands together and alternately raise and lower them."

Roggeveen, unable to comprehend the process of carving and setting up the statues, figured they were clay molds and filled with rocks.

It was nearly 50 years later before another European ship visited the island, this time a Spanish one. Captain Cook called in 1774. By the early 1800s, it became a routine port of call for many of the ships sailing between South America and the South Pacific islands.

The isolation was over but entry into the outside world was hardly beneficial to the islanders. Natives were killed, were carried off as slaves to work in Peruvian mines, were sent home with smallpox.

By the time the island was annexed by Chile in 1888, the population had sunk to around 600.

Today the island is home for about 2,000 people, a mixture of Chileans (continentals or "weeds," as they are sometimes called by the islanders) and natives (or Rapa-Nuis, as they call themselves).

EASTER ISLAND LIES 2,300 miles west of the coast of Chile and 2,500 miles east of Tahiti. The closest human neighbors are 1,400 miles to the west on Pitcairn Island (the place where mutineers of the Bounty sought refuge). The only land visible from the island is above in the heavens, one reason for one of the ancient names of the island: "eye turned toward the sky." Even now most people consider it the loneliest island in the world.

And even today this remoteness shapes the atmosphere and life of Easter Island.

At the airport, the runway has been newly renovated and expanded as an emergency landing site for the American Space Shuttle. But this is about as close as the island comes to space-age technology. For the rest, it is a place out of time, moving through the 20th century at its own pace, and for the most electricity, there are Western-style homes and Western-style clothes (many of the latter bargained off the backs of tourists in exchange for wood carvings and shell necklaces).

The physical look of the land is defined by three ancient volcanoes that form the corners of a lopsided triangle. Much of the island is covered with grass; there are a few trees, particularly eucalyptus brought in from New Zealand.

The islanders still live off the land and the sea and the 2,000 or so tourists who come each year. A supply ship calls from the mainland once a year. For the rest, since the rocky, volcanic coast precludes an adequate harbor, planes fly in and out two or three times a week from Santiago or Tahiti.

The population is clustered into one small town, Hanga Roa. Roads are unpaved, but smooth enough to accommodate the mini-vans used to transport visitors around the island. Jeeps and

horses are the other forms of transportation. The local culture is an eclectic mix of South American and Polynesian. Spanish and Rapa-Nui are spoken here.

Facilities are nice but nothing fancy, and just as well. Nothing would seem more out of place than a flashy island resort. There are two hotels and a variety of guesthouses. Island prices areexpensive.

But you don't go to Easter Island to sit on a beach or laze away on a tropical island vacation. There is only one incredible pull to the island: the past.

As Katherine Routledge, one of the first archaeologists who came to study, noted in 1914, "In Easter Island the past is the present, it is impossible to escape from it; the inhabitants of today are less real than the men who have gone; the shadows of the departed builders still possess the land. Voluntarily or involuntarily, you must hold commune with those old workers; for the whole air vibrates with a vast purpose and energy which has been and is no more. What was it? Why was it?"

A DEBATE STILL rages as to whether the first islanders were South American or Polynesian. But consensus opinion places the first settlers there between 100 B.C. and 400 A.D. And there may have been periodic migrations in the years after.

Rapa-Nui legend tells of the great leader Hotu Matu'a who arrived with a small fleet of canoes around 1100. Archaeologists date most of the great stone statues, or maoi as they are called, from after this time.

They have pieced together much of how it was done. The statues were quarried out of volcanic rock high on the slopes. Scientists think the maoi were transported to special sites, or ahus, near the shore by a series of ropes and tree-trunk poles. There, they were raised by ropes and levers; raising a bit, filling in with dirt and rocks, raising a bit more, until the statues were upright.

When Thor Heyerdahl and William Mulloy and their crews set about re-creating the process, they found it could be done this way without any tools of modern engineering. Mulloy's crew raised seven statues at Ahu Akivi; the first took a month to raise, the last one a week.

A likely explanation, but not nearly as fanciful as Rapa-Nui legend. The maoi, the story goes, were given special powers by the shaman-priests and commanded to walk to the sea.

The statues were carved without eyes. It was only when they were put in place on the ahu that sockets were scooped out and eyes added. Topknots, carved out of red lava from a separate quarry, were also put in place as some of the statues were raised.

Researchers think they were not gods or stone idols, but a sort of ancestor figure that was endowed with super powers and able to protect kinfolk. When a death occurred in the clan, the body was placed in front of the ahu and left until the bones were cleaned by wind, weather and birds. Then the bones were buried in chambers under the ahu. The maoi were also an apparent show of the strength and wealth of the clan.

Which all might explain the purpose behind the statues but nothing uncovered so far has explained the peculiar design. Stone statues have been found on other Polynesian islands but nothing on this scale or with a similar look.

The maoi average 12 to 25 feet in height; the largest finished, transported and set up figure is 32 feet high and weighs approximately 90 tons. An unfinished statue still sleeping in the quarry would have been about 65 feet tall. The red topknots weigh as much as 10 tons.

The design follows a basic pattern, yet no two statues are exactly alike. Most have squared-off heads, prominent foreheads and large broad noses, thin pouting lips and long, long ears. Their short, thin arms lie straight along their bodies, with hands resting on hips. The statues all end just below the naval; sometimes the backs are intricately tattooed. The expression is always brooding, disdainful.

There are approximately 600 maoi on the island; 300, in various stages of development, line the hills of Rano Raraku.

But the statues that stand today and they can be found in several places around the island are ones that have been restored to their former ahus. Around 1600, it seems, an intense Civil War broke out between the "long ears" and the "short ears" that eventually resulted in the capture and slaughter of the "long ears." But not before all the statues were toppled. (Apparently a few were still standing when Roggeveen happened upon the island, but by the time the outside world came in numbers, all the statues had been upended.)

Today the majority still lie just where they fell, face-down on the rocky plateaus. And in their own way, they are as powerful a testament to the cycles of culture as are those that watch over the island from the restored ahus.

Whether you call it Easter Island, as the English do, Rapa-Nui as the Polynesians do, or Isla de Pascua as the Spanish do, the great stone statues are a reminder that for a time this lonely hunk of volcanic rock was known as Te Pito o te Henua the Navel of the World to a small group of imaginative people, the likes of which have not been seen before or since.