The remaining U.S. wilderness: Think of it his way: there's a finite amount of it, and it's shrinking. The wolves of Yellowstone, for example, so successfully reintroduced seven years ago, are again the target of ranchers in Wyoming and Idaho unhappy about losing livestock. Their anger may be understandable, but the proposal to remove wolves from the endangered species list in order to begin killing them just seems plain wrong. Learn why by taking a wolf tour.

Stiltsville, Florida, before it's swept away by a hurricane The novel wooden houses in this onetime resort community off Key Biscayne hover above the water on stilts—as the name suggests—and are accessible only by boat. Built in the 1930's, Stiltsville had its heyday in the late fifties—complete with gambling, police raids, and a place called the Bikini Club. Since then, hurricanes and fires have taken their toll; only seven of the striking buildings remain.

The historic pubs of England, before they're modernized into oblivion There's no shortage of pubs in Great Britain, but every month about 20 of them are closed down or remodeled, old dark-wood interiors and Victorian glass and tile giving way to sleek, clean banality. The U.K.-based Campaign for Real Ale has compiled a list of 250 pub interiors worthy of preservation—and patronage.

The Modernist architecture of Asmara, Eritrea, now being rediscovered When a 30-year war for independence from Ethiopia ended in 1993, visitors began returning to see the astounding collection of 1920's and 30's Italian designs, built during Benito Mussolini's failed imperial expansion. With a loan from the World Bank, the government is now preserving hundreds of the sleek, streamlined buildings in the capital city. The greatest concentration of Art Deco is along the old Viale Mussolini, now called Harnet Avenue.

Old Shanghai, before it's razed to make way for yet more skyscrapers The narrow streets and colonial architecture that define the city are threatened by a maniacal building spree, which has seen more than 2,000 skyscrapers go up since the early nineties. The construction boom may soon slow: scientists have warned that the city is literally sinking into the swamp it's built on, and residents are voicing displeasure at their city's Blade Runner future.

The Great Barrier Reef, suffering because of overdevelopment This vast coral reef, an awe-inspiringly rich ecosystem spread across thousands of miles of northeastern Australian coastline, is threatened by pollution, global warming, and overfishing. Environmentalists want to designate about half the area a marine sanctuary and are supporting eco-friendly tourism.