His mission: to circumnavigate the globe in 80 days. His challenge: no flying. This is the story of one man's quest to conquer the planet—not the well-trod tourist magnets but the forgotten urban corners and textured in-between places, those rewarding rejoinders to globalization that still proffer the true meaning of travel. Mark Schatzker sips it slow

Your average airliner cuts through the atmosphere at 565 miles per hour. But inside the fuselage, the experience is a drawn-out study in nothing happening. You sit there, watching second-run movies and waiting for the flight attendant to return with another round of carbs—an event that takes on the dimensions of drama. Outside your nine-inch oval window, the world is a caricature of geography: just mountains, rivers, roads, and water.

Slow things down and the world yields a steady blast of detail. Driving along a country road in outermost Mongolia, for example, you find yourself scanning the lunar landscape for birds of prey when your attention is diverted by a family of four in the oncoming lane, all riding the same motorcycle. On a train in Siberia, a stand of enormous birch drifts by the window and is abruptly terminated by a town, disheveled and crumbling, its Soviet-era smokestacks long since squelched. In the Channel Islands, a horse-drawn carriage conveys you down a narrow country lane. As you listen to the crunch of wagon wheels on gravel, you pass a windmill erected in 1571 and think: perfect, just perfect. This is the irony of slow travel—the world comes at you a lot faster.

I can tell you this because I recently circumnavigated the globe the old-fashioned way: on foot and by automobile, bicycle, bus, cable car, cruise ship, ferry, horse, kayak, scooter, subway, taxi, tractor, and train—but never by plane or helicopter. I departed New York City on March 5, traveled at an average speed of 14.61 miles per hour, and returned, to the very same spot, on May 24.

I traveled around the world in 80 days.

Eighty days may sound long: 1,920 hours; 115,200 minutes; 6,912,000 seconds. But as any glacier will tell you, covering ground takes time. You have to keep moving.

Take my "slow" day in Cilento, Italy. This was one of only a handful of days during which I didn't have to go to sleep farther west than where I'd woken up. And yet it all got off to a fast start.

I was rousted out of bed at 7 a.m. by my host, Clautilde Vecchio—archaeologist, cook, curer of meat, and quintessential Italian mother—known to everyone as Tilde. I downed an espresso and some homemade bread with jam and butter churned from buffalo milk, and we set off in her Fiat—Tilde and me in the front, her daughter Wanda (pronounced VON-da) in the back. Our quarry: sausages.

By 7:40 a.m., we were racking up the miles. Not serious miles, mind you. I had been clocking upwards of a thousand a day not two weeks earlier on a train across Russia. But as miles go, these were good ones. Driving northeast, we climbed into the green, rounded mountains of Cilento. There were trees: olive, oak, chestnut. There were grapevines. Higher up, there was the sound of bells and, soon after, cows—southern Italy's free-roaming Podolica. We pulled over, and I climbed the embankment to take some photos. That's when the dogs attacked. They were sheepdogs, white with longish snouts, running and barking. Tilde yelled at me to get back to the car but not to bolt because then the shepherding instinct would be replaced by the hunting instinct and I would be taken down like prey. "Lento!" Tilde shouted. "Lento!"