Ken Jennings, the guy you probably know from his epic Jeopardy! winning streak, is a geography nut and acclaimed author responsible for the book Maphead and the Condé Nast Traveler column of the same name. The topic this week is the longest straight-line hike in the world. Originally discovered by Guy Bruneau almost a decade ago, the hike covers an 8,400-mile path from West Africa to the East China Sea that crosses 9 time zones, 18 countries/territories and plenty of hazardous terrain in a perfectly straight line. The “great circle” path obviously doesn’t look like a completely straight line because the Earth isn’t flat, but you get the idea. No one in the world has ever attempted the trek because of the inherent risks—Dutch adventurer Bart van Eijden says anyone attempting it is out of their mind—but with a potential Guinness record on the line someone probably will eventually. If that person is you, make sure you bring a great travel backpack.