By Tom Verde, Globe Correspondent

AXUM, Ethiopia - This must be the world's only tourist destination where the most famous attraction is something nobody is allowed to see.

According to local tradition, this northern Ethiopian town is the final resting place of the Ark of the Covenant, the gilded wooden chest containing the stone tablets of the Ten Commandments which God Himself delivered to Moses on Mount Sinai. This incomparable archeological treasure, legend has it, was brought to Abyssinia (as Ethiopia was known) from Jerusalem 3,000 years ago by Menelik, son of Solomon and the queen of Sheba. It now resides, say the faithful, within the walls of Axum's St. Mary of Zion chapel, off-limits to all but a solitary priest who serves as the ark's custodian.

Like countless other visitors to Axum - the holiest city of the Ethiopian Orthodox Church and the ancient capital of Africa's oldest Christian nation - I got no closer to the ark than the wrought-iron fence surrounding the chapel's squat, mausoleum-like exterior. Had I tried, I was told, I would have burst into flames.

There are plenty of noncombustible sights to see in Axum, however, including the world's tallest obelisks, and numerous tombs and ancient churches. Otherwise, this seems only another dusty agricultural town set in the sub-Saharan hills of Tigray province, about 20 miles from the border with Eritrea.

But from around the time of Jesus until just after the rise of Islam in the early seventh century, this remote outpost was the bustling capital of a wealthy trading empire that stretched from the Nile Valley to southern Arabia. In the eyes of contemporary chroniclers, Axum ranked with Rome, Persia, and China as one of the four great kingdoms of the ancient world.

Rich and powerful, Axum's kings had tamed elephants to pull their chariots, pet giraffes for their amusement, and so much tribute rolling in that, even today, gold coins are sometimes washed to the surface among Axum's ruins after a hard rain.

Of course, you don't get your hands on that kind of wealth by raising goats and growing millet. The Axumite empire was instead built upon one of history's most potent economic catalysts: greed.

Being in the right place (along the busy commercial shipping lanes of Africa's Red Sea coast) at the right time (the heydays of the Roman and Byzantine empires), Axum's merchants controlled the flow of most luxury goods between India, Africa, Arabia, and the Mediterranean. Gold, emeralds, obsidian, frankincense, myrrh, ebony, ivory, tortoise shells, rhino horn, ostrich feathers, cassia bark - you name it, Axum's kings and its merchant class were about the only ones between and Asia and the Roman world who had it, and they knew it.

''The ruler of these regions is Zoskales, a stickler about his possessions and always holding out for getting more,'' wrote one Greek sailor-merchant. Even purveyors of less glamorous merchandise drove hard bargains. An inscription on the bottom of one pot found at Axum, translated, reads: ''He who breaks it, pays!''

In addition to their reputation as shrewd businessmen, the Axumites were famed builders and few visitors have failed to be impressed with the city's remarkably well-preserved monumental obelisks, known as stelae.

Erected in the third and fourth centuries, at the height of Axumite power, some stelae are now little more than stubby, bullet-shaped chunks of granite sticking out of the ground. Others are towering, remarkably well-preserved monoliths, intricately carved in the layered style of Axumite royal architecture, with its rectangular window tracery, massive door knockers, and protruding, rounded crossbeams. Although some believe the stelae served an astronomical function, most researchers agree that they were tomb markers for Axum's kings.

In a testosterone-driven effort to outdo one another, each succeeding monarch made sure his stela was bigger than his predecessor's. Thus, by the first quarter of the fourth century, history's tallest monolith - taller even than any raised in Egypt - towered nearly 110 feet above Axum's skyline.

But not for long. Whether it toppled soon after it was erected, or crashed to earth before it ever stood upright (theories vary), the city's largest stela still lies where it fell, in a half dozen or so broken pieces, like an abandoned pile of children's blocks.

Axum's tallest standing monument is the King Ezana stela, named for the fourth-century ruler who converted to Christianity, making Ethiopia the first African nation to adopt the faith as the state religion.

Isolated from the rest of Christendom by distance and imposing mountain ranges, the Ethiopian church was essentially left to develop on its own. What emerged was an eclectic blend of Christianity and pagan mysticism (incantations and spells against evil spirits) together with elements of Judaism (circumcision and abstention from pork).

By the middle of the fourth century, the substitution of the cross for the pagan symbols of the disc and crescent on all of Axum's coins meant Christianity had become the dominant religion. Dozens of such coins, as well as other treasures, are on display at the National Museum, inside the St. Mary of Zion church complex, just across the street from the northern stelae field.

Unfortunately, the contents of many of the display cases are so jumbled they look like the inside of a junk drawer. Still, the museum houses many exquisite items that make it worth visiting, like delicately inlaid jewelry or fluted glass stemware that wouldn't look at all out of place on a Bloomingdale's bridal registry shelf.

Fortunes, however, come and go. While commerce had made Axum what it was, its vagaries ultimately led to the empire's downfall. First, the climate changed. Lack of rain left farmers little to harvest but dust. Then, the expansion of Islam took its toll. Arab domination of the Red Sea shipping lanes in the sixth century effectively put the Axumites out of business. The city was left weakened and defenseless by a series of Muslim invasions that followed.

''Encompassed on all sides by the enemies of their religion,'' wrote Edward Gibbon in ''The Decline and Fall of the Roman Empire,'' ''the Ethiopians slept near a thousand years, forgetful of the world, by whom they were forgotten.''

Yet, not entirely.

For the visitor in the present, Axum of the past is never far away. Camel caravans still lumber past the stelae field daily, laden with market goods. Donkeys bearing bloated, sweating water-skins still trot through the dusty streets, urged along by chattering children with reed switches. And, if you happen to be there on one of several Ethiopian Orthodox holy days during the year, you might catch a glimpse of the ark (albeit shielded from view beneath a cloth) as it is paraded through the town by a chanting cadre of priests. Shaded by silken umbrellas, symbols of the heavens, with their incense burners swinging, drums drumming, and sistras clanging (cymbal-like musical relics that date back to the Egyptian worship of the goddess Isis), the Ethiopian clergy put on quite a show - one that the ancient Israelites themselves might have recognized.

'And they ... went before the ark,'' wrote the author of II Samuel 6: 4-5. ''And David and all the house of Israel played before the Lord on all manner of instruments made of fir wood, even on harps, and on psalteries, and on timbrels, and on cornets, and on cymbals.''

The only modern addition to this orchestra, used by Ethiopian Orthodox priests during public ceremonies, is an instrument any pastor whose congregation tends to drift now and then would surely appreciate: a bullhorn.