Our fundamental notions of travel and adventure hark back to the Romantic movement of the early 19th century; they will need some radical revision as we step toward the year 2100.

The veteran circumnavigator David Lewis got it right, I think, when he told me a few years ago that the heroics of rounding Cape Horn (something he'd done several times) were greatly exaggerated. "It's just because there's no city there," he said. He was comparing the Horn with Africa's Cape of Good Hope, where, when the west-flowing Agulhas Current breaks into the teeth of a westerly gale, huge, steep, ship-swallowing seas invariably result. But the horrors of rounding the Cape in the wrong weather take place within shouting distance of marinas, insurance towers and branches of McDonald's, and it is the great Romantic fallacy that wilderness cannot be truly wild in such close proximity to urban civilization.

Yet the whole surface of the globe is now proximate to the city, and 100 years from now it will no doubt be unimaginably closer. In 1999, adventure-travel outfitters were hauling parties of hikers up and down Mount Everest in a continuous shuttle service. Antarctica had become a luxury tourist destination. On the most recent solo round-the-world yacht race, sailors floundering in the Screaming Sixties of the Southern Ocean were posting daily e-mails, to be read on the Internet by armchair sailors like me, within minutes of their arrival at race headquarters. The search for the ever more remote (in northern Alaska, the Northwest Territories) has become a fools' quest. Already, the word "wilderness" now usually means "wilderness area"--a park, really, complete with permits, rangers, posted trails, rules and regulations. In 2100, most of these parks will be closed to all but a few privileged visitors, to maintain the habitat of wolves and bears as a museum piece.

Lewis got it right again when he marveled to me at his near-dismasting in, of all places, Juan de Fuca Strait. The most experienced and far-traveled sailor I've ever met almost came to grief, on a sunny afternoon in late summer, sailing between Friday Harbor, the tourist center of the San Juan Islands, and Seattle--a trip of less than 60 miles. He hadn't reckoned on the afternoon gale that springs up here when the overheated land sucks in a fresh supply of air from the cool Pacific. In minutes (he said "seconds"), a dog's breath of sea breeze became a 50-knot blast that blew out Lewis's headsail. "It's so bloody sudden, your weather," he said, and I felt a glow of vicarious pride in the power of the sheltered waters of the Pacific Northwest.

Wild is wild--in Juan de Fuca Strait as off Cape Horn--and it is the wildness at our own back doorsteps that we must learn to revere in the century ahead: the stroll through the woods, the wild birds visiting the feeder at the kitchen window, the real and exhilarating danger of our domestic seas. In the 20th century, we traveled too far and too fast, without ever traveling very deep; idly skimming the surface of the world in pursuit of the merely distant and the merely exotic. One hundred years from now, we shall have to learn to travel deeper, more seriously (which means more slowly), and much closer to home.

Jonathan Raban is the author most recently of "Passage to Juneau: A Sea and Its Meanings" (Pantheon).