Enterprising travellers are racing against the clock to see endangered cities, sites and wildlife before they cease to exist.

Euromonitor International, a global market research firm, reports that "the exotic flavour of alternative regions" is a strong draw for Canadian tourists, while substitutes for the traditional vacation in the U.S. has become a "dominant trend."

Booking agent Expedia.ca was among those at the forefront of the shift when it teamed with the United Nations Foundation in 2005 to promote sustainable tourism to World Heritage sites. The numbers of tourists interested in travel of this kind have grown dramatically since then, as have the number of tour providers, .

"Travellers hear about endangered places -- rainforests especially -- and it has an effect where people become more urgent [about visiting]," says Shawn Zimmerman, a Montreal-based research analyst for Euromonitor.

History buffs hungry to see one of the world's largest collections of petroglyphs, for example, have little time to get to the Diamer region of Pakistan. A planned dam and reservoir system are expected to obliterate the ancient Buddhist artworks within five years.

Other spots in jeopardy either due to human intervention or natural forces, include the Chan Chan Archaeological Zone in Peru, the ice fields of Mount Kilimanjaro in Tanzania, the historic town of Zabid in Yemen and the Great Barrier Reef in Australia.

"We're losing our heritage faster than we can document it, never mind preserve it," says Francois LeBlanc, head of field projects for the Getty Conservation Institute.

"We can't stop tourism to these [endangered] places. And actually, it's going to continue to increase at a very alarming rate . . . So we have to figure out how to better manage it."

Tibet, for example, saw 2.25 million visitors in the first 10 months of 2006, representing a nearly 32-per-cent jump over the previous year. The sanctity of the region's religious sites is being disrupted by the increased traffic and resulting business development -- twin threats that loom even larger with a luxury train between China and Tibet set to go into operation.

The Galapagos Islands, added to the World Heritage Danger List this year, has seen the number of visitors more than double in the last 10 years, jumping from 60,000 in 1996 to more than 140,000 in 2006. Scientists say this poses an increasing threat to the survival of many of the islands' species, which are not immune to germs introduced by travellers.

Closer to home, however, there seems to be less anxiety about seeing nature's attractions before they're gone. Attendance at Glacier National Park, whose namesake attractions may vanish by 2030, has decreased from 2.03 million in 2004 to 1.9 million in 2006.