TO the untrained thrill-seeker, Yemen would seem to promise the kind of adventures that only James Bond would relish: kidnapping by tribal factions, riots over gasoline prices, cheap and plentiful AK-47s, and taxi drivers who pack daggers and pistols. Plus, there’s the specter of terrorism: the bombing of the U.S.S. Cole in Aden in 2000 presaged much bigger attacksTO the untrained thrill-seeker, Yemen would seem to promise the kind of adventures that only James Bond would relish: kidnapping by tribal factions, riots over gasoline prices, cheap and plentiful AK-47s, and taxi drivers who pack daggers and pistols. Plus, there’s the specter of terrorism: the bombing of the U.S.S. Cole in Aden in 2000 presaged much bigger attacksSkip to next paragraph

But in contrast to the rest of the Arabian Peninsula, which is mostly hot, dry and barren, Yemen is practically a cool green paradise, with crisp mountain air, enormous acacia trees, pristine coral reefs and verdant fields bursting with khat, a psychoactive plant that induces mild euphoria.

In recent years, tour operators have started to capitalize on Yemen’s exotic geography as the new frontier in adventure travel. New outfits offer grueling treks to mountaintop villages, four-wheel-drive safaris through untrammeled deserts and sailing voyages aboard ancient dhows to isolated, Galápagos-like islands. And unlike Dubai, the Oz-like emirate on the other side of Saudi Arabia, Yemen is nothing if not authentic.

Yemen is also safer today, thanks to post-9/11 ties between Yemen and the United States that seem to have quieted tribal tensions and undermined terrorist operations in the country. A steady stream of European adventurers have already arrived.

One of the more intrepid tours is offered by Arabia Felix, a tour company based in Dubai. It has started two-week-long safaris that snake from Dubai across Oman, and along old frankincense trading routes into eastern Yemen. Guests alternate between camping alongside desert nomads and staying at luxurious places like the Al Hawta Palace Hotel, a former Yemeni palace in Sayun.

Visitors get to see “an Arabia with no borders,” said Marco Livadiotti, one of the principals of Arabia Felix.

After crossing into Yemen, the journey continues through the fabled Empty Quarter of the Arabian Desert, the world’s largest stretch of sand. Then it proceeds to the fertile green valley of Wadi Hadramaut, home to Yemen’s two most atmospheric towns. The walled city of Shibam has a skyline of tall mud-brick houses, earning it the nickname “the Manhattan of the Desert.” Nearby, the ancient town of Tarim has 365 mosques, one for each day of the year.

The final leg of the journey, from archaeologically rich Marib to the capital, Sana, is a bit dodgier and requires an armed Bedouin escort because of tribal unrest.

For those who want to explore by foot, the Haraz Mountains along Yemen’s western edge are a hiker’s paradise. The region is linked by well-worn trails that cut through fields of prized khat, zigzag across lush green mountaintops and pass through fortresslike villages of mud and stone houses.

Along the way, you can pitch a tent, check into small village guesthouses, or luck out with an invitation to stay at someone’s home. Yemen may seem chaotic, but old-school Arabian hospitality, especially toward foreigners, almost always prevails.

Yemen’s most far-flung adventure is undoubtedly the island of Socotra, a time capsule 210 miles off the coast in the Indian Ocean. Socotra is an alien world, even to most Yemenis. Natives speak an obscure language, Soqotri, that is virtually unintelligible to mainlanders. The fauna and flora of this island evolved separately from mainland Arabia.

Until recently, the island could be reached only by boat and was cut off from the rest of the world during the monsoon season, June to September. Now flights land year round, bringing scuba divers to spectacular reefs that are only beginning to be explored. There are steep limestone cliffs that plunge into dark chasms, a colorful bounty of coral and other rich (and endangered) marine species like sea turtles and groupers.

Inland, you can hike up the Haghier Mountains, camp on a beach or go off-roading along the wadis (dry riverbeds), where you might come across endemic birds and plants like the dragon’s blood tree, which leaks red liquid when cut.

But the most exotic encounter on Socotra may be its people, descendants of both African and South Arabian tribes, who have developed a culture unique from any other place on the planet. Even today, the islanders seem to live as they want, not to please or profit from the few tourists who reach their home.