Famous explorers have flown from pole to pole. Icebreaking ships have churned from deepest south to farthest north. PBS and Michael Palin have even turned the top and bottom of the globe into comedy TV.
Still, I will not be deterred. So what if it's been done? I'm going to do it again, and do it my way.
My plan is this: I want to get as far from the equator as I can while staying where there are roads and towns and keeping to the Americas. I want to explore not ice caps, but the extremes of where people and animals live year round.
And I want to do both South and North in one month.
Day of the Penguin First, I spend a week in Patagonia, about as far down as you can get without hitting Antarctica. And I am prepared. Thinking palm trees and coffee plantations, I have stuffed a suitcase with T-shirts and shorts. It is only the first of October, after all.
But when I get to the town of Punta Arenas at Chile's southernmost tip, I am reminded about changing hemispheres. Instead of mellow early fall, it is the edge of spring here, in the 30s, and a tigerish wind growls all night long.
Despite the cold, I am instructed to rub on sunscreen. ''The hole in the ozone," warns our guide, Enidio Villanueva. ''Not just Antarctica. It is here."
The airport and the town are home to hardly anyone who knows English, yet I am welcomed by Dunkin' Donuts franchises around every turn. Chilean coffee tastes awful, but I could, if I wanted, get some Munchkinos and a bebida (beverage) for little over a dollar.
Our little tour group loads up a bus named ''Teresa Fernandez" -- we can tell this from a handwritten sign up front -- and after a ride to the town of Puerto Natales, a beat-up Land Rover bangs and bounces us into the terrain of Torres del Paine National Park.
The scenery spreading out is like a mix of Scotland and Alaska. The torres themselves (blue towers) look more like jagged horns than mountains, and the lakes are all an impossible blue from the minerals that tint them.
Everywhere are herds of guanaco, cousins of the llama, posing like lookouts at the tops of ravines to make sure we drive on.
We hike to a lime-colored waterfall where puffs of wind shower us with gravel -- painful pieces -- and with icy foam. Reminded of Christmas, we look up and point at sprigs of mistletoe in the branches of the trees.
Southern Patagonia has its own ice field, like Antarctica or Greenland, and after a bus ride into Argentina, we are suiting up to walk around on top of the famous Perito Moreno Glacier, considered one of the country's great natural wonders. We've got to take a boat from near the town of El Calafate that sails through crme de menthe and lands us at the base of a jaggedly-frozen cliff-sized Carvel dessert.
The glacier top is pointy and pure white, but the cracks in it are inflatable-pool blue. As a new set of guides is outfitting us with crampons, we hear a boom like thunder. It is Perito Moreno grumbling. He is not pleased.
Up we stomp, crampons cutting into slush, and worrying about the sign warning of how tourists have been killed. ''Danger," it said simply. ''When ice breaks, pieces of it are thrown violently dozens of meters away."
OK, I think. Walk and listen. We don't get flying ice, although climbing here turns out to be strange and dangerous. You can't rely on crampon edges as you would with skis, and you step over and around shiny aquamarine caves and deeply frozen holes like wells.
We scoop water from a cascade and pool that have been carved wildly by wind, water, and ice, and chip off pieces of the glacier itself, to taste. It is like a drink of winter.
The end of my Southern Hemisphere trip will be by sea. I am in Ushuaia, Argentina, which along with nearby Puerto Williams are the world's southernmost cities. Houses and hotels here are painted cheerfully, like props from an electric train set, but there is barely enough time to get them on film.
I am boarding the Mare Australis, a not very big but shipshape Chilean cruise ship that will take me ''around the Horn." Cape Horn. The Strait of Magellan. Beagle Channel, named for the ship that brought Charles Darwin here.
All of those famous names make me feel like an actual ocean explorer, and by mistake, I am assigned the cabin reserved for the ship's chief engineer, who apparently is not on board. The captain's stateroom is directly across the hall, and right next door I push open a hatch that says ''Puente." When I see a polished wheel I know I am sleeping inches from ''the bridge."
Passing Cape Horn, the southernmost continental tip, the water gets choppy right at the point where Atlantic blends into Pacific. We can see a clearing and a monument on the Cape itself. It is in the shape of an albatross, and all around us the real things, with their mighty wingspans, wheel and dive. Scores of ships have cracked up on the rocks just below.
When the ship gets to Wulaia Bay -- an amazing purple and gray place with far-off snow caps -- we passengers load into motorized rubber rafts for a hike on shore. If we fall into the ice-chunk-cluttered water, I am told, we will shortly die, even though we are outfitted with the cruise line's rain slickers, fishermen's overalls, and Paddington-bear-style boots.
We look at one another, and we look at the water, and we grab on.
The last of our shore trips lands us on the beaches of Magdalena Island early in the morning. This is just a lump in the sea, but it is populated with penguins -- breeding Magellan penguins who are busy shoveling trenches for eggs or walking around the island single file.
''Pinginos," says the guide from the ship, Mauricio. ''Muchos pinginos." One hundred twenty thousand, we are told, plus thousands of dangerous mounds of guano and thousands upon thousands of holes. ''Do not use the flash," instructs Mauricio. ''Why? Because the flash, it is not good for the eyes of the penguin."
The Eyes of the Penguin, I think. It sounds like a spy movie, and in fact I start to feel the eyes of black-and-white-striped penguins upon me as I trudge around in my boots. They look as if they are tussling with their beaks, or nuzzling, or settling back to emit their cries like notes from a kazoo.
But I know better. They are watching. Like the guanaco lookouts. Like the Perito Moreno Glacier that, as we approached it, was not pleased. ''You are a northerner," they would say if only I could understand them. ''You have seen enough of our southern world. It is time for you to go."
Night of the Polar BearBottom of the world: Been there, done that. Now, bring on the top.
It is still October, but late in the month, and I sign up for an adventure tour to the not-quite-North Pole. You can get farther north, in Alaska, Canada, and elsewhere, but I don't have much time, so I go for an organized trip, one that has us aiming for bear. Polar bears, that is, roaming the subarctic tundra near the outpost of Churchill, Manitoba.
When I look at a map, I note that the Arctic Circle is at latitude 66.6. Churchill, on the western edge of Hudson Bay, sits at 60. I throw in wool socks.
In Winnipeg, it is snowing already. We cram into a chartered prop plane that says on its side that it is run by ''Calm Air." The flight is punctuated by jolts that throw my orange juice into the aisle.
I try to distract myself with the in-flight magazine. ''Winter Living," teases the cover. ''Cure your cabin fever! Cook up comfort food! Cool cold-weather clothes!" It's going to be a very long ride.
Churchill, I discover, is a scattering of streets and insulated sheds, but it is also where polar bears arrive each fall in late October and early November to wait for Hudson Bay to freeze. As soon as it does, they pad out onto the ice to hunt seals.
Tundra, tundra everywhere. Our guide up here, a German named Matthias Breiter, tells us that ''tundra" is the land that doesn't have any trees and that the patches with scraggly forest are called ''taiga."
Forest? You can spot a few toothbrush-thin spruce trying to grow. But mostly there is wind and snow and a kind of distant cousin of daylight. I check my watch: 1:43 p.m. According to the light, it should be at least 5 o'clock.
On the ride from the airport we all yell and point. Three shapes that look like pictures in calendars plod along by the side of the road. It is a mother bear and cubs. Lens caps are dropped, windows on the bus are ajar, and shutters snap and snap.
These are not zoo bears. Not at all. Their fur is puffy, not yellowish or matted. And while the cubs are shy, their mom is confident and alert, like a cop on the beat.
We are in her world now, and it is we who unload our bags into a kind of cage. Our home for five days will be a specially-built, movable tundra lodge: four train-style cars linked together and jacked up on huge ATV wheels. There are Pullman-like bunkrooms for tourists, there are lounge and dining cars, there are decks with steel gratings, and there are polar bears.
Bears licking the tires under the lodge. Bears snuffling inches from our shoes out on deck. Bears growling and arguing. And bears staring up the open drains when you are trying to get clean. When I take a shower, I look down while rinsing the shampoo from my hair and see a medium-sized male watching carefully from below.
Every night we look at northern lights -- a glow-in-the-dark Frankensteinian green. Every day, we pile into a moon-buggy to ride away from the lodge in search of yet more bears. The buggy is cold, and we get bitten by an arctic wind that whistles with the zest of the insane.
Someone shouts about a snowy owl they can see. Maybe it's a rock, we say. It is probably an owl, decides our guide. When it tips its feathery head we know for sure.
Seconds later we spot an arctic fox that pops up, then disappears behind a bank of snow. He is whiter than the white of the landscape and surprisingly small. My cat, Sam, outweighs him by a good five pounds, but this fox is fast -- trotting and darting until he is out of sight.
Our last day of the tour is spent in town, and we are warned that there can be bears in Churchill, too.
The last time anyone got mauled here was in 1983, we are told. For reasons no one can explain, a local man went for a walk at night after filling his pockets with meat. A polar bear ate him and the pocketed meat as a single meal.
None of this is reassuring, and we look carefully around corners and spend a lot of our time inside bars and stores.
Aggressive Churchill bears end up locked inside a former military hangar. And now and then, on crisp and clear afternoons, they are given an extra-large dose of something to relax them and then are helicoptered far from town.
Before our group heads to the airport, we go to a hangar to see a deeply slumbering bear as he is stretched out into a hammock-like net, winched up by the copter, and then swung, high and swaying, into the blue-black arctic dome.
''Calm air," I say to myself. Calm air.
Peter Mandel of Providence writes children's books, including ''My Ocean Liner" (Stemmer House).