Unlike most visitors to Jamaica, Kofi Agorsah couldn't care less if it rains. After all, the black-studies professor from Oregon comes not for the sun and surf but to trek into the rain forest and study the Maroons, descendants of escaped slaves from the 18th century. Since UNESCO put the Maroons on its list of 47 endangered cultures this year, Agorsah says he sees a lot more tourists on the trail. "[The Maroons] are difficult to get to," he says. "You really have to want to go."

Growing numbers of travelers are trading sunscreen for spiral notebooks and forgoing relaxation for mind expansion. The World Tourism Organization recently announced that cultural education makes up the fastest-growing segment of the tourism trade. To answer the demand, museums, universities and wildlife organizations are offering programs to study everything from paleontology in Mongolia and volcanology in Hawaii to bullfighting in Spain and marine life in the Mediterranean.

National governments are catching on; the tourism board in Spain is currently looking for ways to shift its focus from beaches to monuments, sites and heritage. And on the Hawaiian island of Oahu, the Polynesian Cultural Center doubled its advertising budget this year to promote local music, dance and food festivals. "Most people have done the well-traveled path of leisure," says Edan Harvey of Traveller, the British Museum tour operator, whose expert-led cultural tours have grown 200 percent in the past nine years. "Now they want to know how the world ticks."

The key to a successful education vacation is having a qualified instructor. Since the United States and Britain dropped travel restrictions to Uganda two years ago, London-based Volcanoes Safaris has seen a 25 percent increase in requests for primatologists to serve on treks as gorilla guides. Before leading a group into the bush to see silverbacks up close, the primatologist organizes morning lectures on things like how to interpret the animals' social structure. "It made the trip more worthwhile," says Meyer Saltzman, a Colorado accountant, who recently returned from a trip in which he got to watch large groups of gorillas playing "just like ordinary children." The Oxford University Society of alumni invites professors as travel guides. The most popular trip: Springtime in Roman and Medieval Provence, led by a professor of modern languages who gives lectures during tours of ancient ruins.

That doesn't mean there's no room for fun. Massachusetts retiree Emily Fisher recently studied Buddhism in Tibet and Mongolia with a curator from the American Museum of Natural History (AMNH) Discovery Tours. "There are some people who take notes," she says. "But I find that a distraction." Hotels are adding learning packages and free workshops on leisure pursuits as well. Hotel Cipriani in Venice brings in professional card players to teach guests how to play bridge. And at Camelback Inn in Phoenix, Arizona, the Zen of Art class is overwhelmed by the number of guests eager to learn how to compose desert photographs.

The shared purpose of learning holidays often leads to friendships that might not otherwise form. Dinnertime discussions over the day's events can be animated, and tend to eliminate the awkward silences that can exist between strangers. "You kind of wear out 'How many children do you have? How many grandchildren?' " says Fisher, who has been on 20 AMNH trips. It's far more interesting to find out why the silverbacks your companions saw that day liked to bluff a charge.