British explorer David Livingstone once described Zanzibar as ''Stinkibar'' for the filth and pungent smell of decay on its shores and ancient streets. Now, more than a century later, the Indian Ocean island off Tanzania is trying to reclaim the mystery and romantic allure normally associated with its storybook name. Eager for the foreign currency that tourists bring, authorities are cleaning up Stone Town, the picturesque heart of Zanzibar where most of its monuments lie. It is a legacy of the days when Zanzibar was a major slave and spice entrepot visited by British adventurers, pirates, Persians, and Portuguese and Arab traders. ''No one wants to visit a filthy and damaged town,'' says architect Ahmed Ahmed, who is the director of the Stone Town Conservation and Development Authority. ''Ten years ago, no one would walk through Stone Town without thinking twice. We lost lives from buildings falling down.'' Walking past a dilapidated building with splintering wood holes, he frowns at a giant cobweb where a four-inch spider lurks. ''Here you talk about history. Zanzibar was a center for East Africa for centuries. It is crucial to preserve the town.'' There are few places in the world with as evocatively exotic a name as Zanzibar. But although it lies just one hour by boat off the coast of Tanzania, many tourists omit it as they pursue the East African safari trail of game parks and nature reserves. Mainly budget travelers and backpackers have followed in the footsteps of Livingstone, exploring Zanzibar's coconut-lined empty white beaches, Arab ruins, and savory Swahili curries. These travelers have had to themselves the forts, bazaars, baths, mazelike narrow streets, dhows (ships), and plantations of cloves and perfumes, all of which are largely unchanged from their past centuries of glory. Zanzibar is closer to Arab culture than to African in sights and sounds. Some 90 percent of the 600,000 islanders are Muslims, and mosques in every village call the faithful to prayer. Veiled women walk through the streets where big verandas and ornately carved wooden doors adorn the whitewashed buildings, a scene reminiscent of Morocco or the Persian Gulf. Zanzibar has absorbed the influences of the other cultures that settled along the way, and the collision has created a unique style, complete with intimate courtyards and overhanging balconies. The multimillion-dollar project to restore Stone Town - which takes its name from the stones laid in the ancient walls - has drawn foreign benefactors, including UNESCO and the European Union, keen to preserve the rich past. Scaffolding holds up crumbling buildings in the labyrinthine streets, where the aroma of orange peels hangs in the humid heat. Multicolored stained glass is being polished, wooden windows newly lacquered. Rubbish is being collected regularly, sewage pipes are being unblocked. A big educational drive is under way to instill civic pride among residents. Mr. Ahmed says the restoration plan launched almost a year ago includes strict building codes. For instance, no more hotels will be allowed to add to the plethora of signs for guest houses that have suddenly sprung up over the past couple of years. Among those being saved now is the House of Wonders, a former sultan's palace that is an architectural fancy with an eccentric clock tower, which looks like it is straight out of ''The Addams Family.'' Restorers are also working on the massive old fort, built by the Portuguese in 1700 in a distinctly Moorish style. Another architectural gem being repaired is the Old Dispensary, overlooking the harbor. It is an extravagant blend of styles complete with baroque stone pineapples jutting out of incongruous corners, vast inner courtyards, and splashes of color everywhere - like a child's fantasy of an Arabian Nights palace. Stephen Battle, the architect overseeing the renovation being financed by the Aga Khan (spiritual leader of Ismailian Muslims), gingerly steps among exposed planks to express admiration for the imagination of the building's creators. ''Zanzibari architecture is a unique hybrid. It's a collision of order and baroque eccentricity,'' he says. ''It is a privilege to work on such a building.'' The hope is that the restoration of Stone Town will not only draw more revenue but also a classier type of tourist. The relaxed mores, public drinking, and skimpy attire of the backpacking crowd has irritated many locals, who complain about a lack of respect by what they describe as modern-day barbarians. Authorities say the budget travelers have brought a rise in crime and drug use. ''That is cultural pollution,'' says Stone Town resident Yousef Amoud, pointing at a bare-shouldered, bare-legged Italian tourist strolling with a beer in one hand and her other arm around a male companion. ''There is a negative impact of tourism for people on the island. The way these tourists dress and behave is not suitable to us Muslims.'' Zanzibar's Chief Minister Omar Ali Juma said in an interview that he believed the worst was over for undesirable tourism and a more desirable crowd was coming in. ''We now lay stress on high-class tourists, who respect and value people's traditions, culture, and customs. Also we try to locate tourist resorts away from the villages to avoid clashes of customs. All in all, the negative impact that had threatened to emerge in the beginning has been controlled.''