If a thing is worth doing, it's worth doing under ludicrously difficult, not strictly necessary, self-imposed rules. Such was the thinking of 31-year-old Graham Hughes when, stewing on the details of a long-dreamed of plot to visit every country on Earth, he decided to add a bit of hot sauce: He would visit them all in one continuous journey, and — to hell with it — he'd also do it without flying. Why not?

More than a few folks told him it was impossible, or stupid, or that "because it's there" no longer flies as a valid motive for adventure. But at the time of writing — 17 months after he pushed off from his home city of Liverpool in northwest England — Hughes has visited 155 of his targeted 200 countries, entering the "Guinness Book of World Records" along the way.

Consequently, every nation in the Americas, Europe, Africa and the Middle East now bears his footprint. If he makes it to the end, he'll be the first person in history to visit every single country on the planet without using air transport.