Sixteen hours on a plane may sound like a nightmare for many, but for passengers on Cathay Pacific’s non-stop flight from New York to Hong Kong, this route, one of the world’s longest, is also among the most scenic. Instead of flying west over North America and the Pacific, the plane turns due north and arcs up and over the North Pole before descending down over Russia and China into Hong Kong. It’s surprisingly faster (by around two hours), and a smoother flight than heading out over the ocean—with the bonus of a rare peek at the high Arctic.

Although planes have been flying across the Arctic for more than fifty years, it was only in 1998 that airlines began to use the transpolar airways we use today. Similar to highways in the sky, these are set routes airplanes follow between points, tied to altitudes and geographic coordinates. In addition to the introduction of newer, more fuel-efficient aircraft, which eliminated the need for fuel stops in Alaska along the way, Boeing notes that polar routes only became popular in the 2000s thanks to “increased access to Russian airspace, the gradual liberalization of bilateral agreements, and growing demand for international service to and from China.” Put simply? You can partially thank the end of the Cold War for shaving an hour or two off of some of the world's longest flights.

Routes from the East Coast and Midwest to Southeast Asia and China typically fly this way for the time and fuel savings; it’s just that the most beautiful hours of flight, when opening the window shade yields views of vast sheets of sparkling ice, happen when passengers are fast asleep. But for those who awake and manage a glimpse, the reward is worth a brief eye adjustment to the stunning brightness. But how can a passenger actually see this from so high up? Thank science: In order to prevent the aircraft’s fuel from reaching its freezing point of around -50 degrees Fahrenheit, transpolar flights occasionally descend to a lower altitude over the Arctic, sometimes by as much as 10,000 feet, to an altitude ever so slightly warmer for the fuel—and ever more picturesque for the passengers.

Still, not just any airplane can make the long trip up and over the top of the world. Jets operating on transpolar routes must follow strict safety policies and carry extra gear, including two or three cold-weather suits for crew in case of an emergency landing; specialized communication equipment; and recovery plans for stranded passengers. Should an emergency occur while your plane is high over the Arctic, the flight crew will be ready with pre-planned diversion airports (not that Tiksi, Russia or Alert, Nunavut are ideal surprise stops on your vacation).

Be sure to grab a window seat if you’re flying from Los Angeles or San Francisco to Dubai or Abu Dhabi, as it’s not only travelers to East Asia who are privy to Arctic sights; routes to the Middle East from the West Coast also often pass over the area near the North Pole.

And what about the Antarctic? While it may seem like Arctic airspace is a veritable thoroughfare for long-haul flights, the story is very different in the Southern Hemisphere. Lack of airports for diverting in case of emergency and security restrictions keep scheduled flights from flying over the South Pole or, indeed, the “White Continent” as a whole. Occasional “photo flights” on chartered Qantas Boeing 747s make special trips for Antarctica flight-seeing, but the standard for Antarctic tourism remains epic voyage by ship.