(CNN) — Once upon a time there was basically only one way for an ordinary person to visit Antarctica -- climbing aboard a small cruise ship and visiting the frozen continent en masse with hundreds of other passengers.
Since the legendary Lars-Eric Lindblad led the first traveler's expedition in 1966, visiting the Antarctic has been on the travel bucket list of many dedicated globetrotters.
Most of the more than 50,000 tourists who visited Antarctica during the 2017-18 season were on cruises, but many cool and highly creative new ways to experience the bottom of the Earth have emerged in recent years.
The latest generation of close encounters of the Antarctic kind runs a broad gamut from marathon running and downhill skiing excursions to sailing, scuba diving, kayaking and even overnight camping.
Most of Antarctica's visitors arrive via cruise ships, but there are more and more ways to explore.
While not nearly as grueling as heroic explorations by the likes of Ernest Shackleton or Roald Amundsen, some of these trips are genuine adventures. They offer a chance to venture where few human beings have gone before -- and in some cases, perhaps no one.
"More people have stepped on the moon than set foot on many parts of the Antarctic," says Iain Rudkin, a Scotsman who leads climbing trips for Antarctic Logistics & Expeditions.
He says this is especially true of the many peaks along the Antarctic Peninsula. "You get a bit feral climbing in the Antarctic," says Rudkin, a 10-year veteran of the continent who started his career as a guide for the British Antarctic Survey.
"It's much colder than other places I've climbed, including the Himalayas. I've been climbing here in -40˚ Celsius temperatures. The other big difference is remoteness. If something goes wrong, there are no Sherpas to carry you down the mountain or helicopter coming to the rescue. But some people crave that danger."
Great white wilderness
Skiing is a strenuous -- and spectacular -- way to experience Antarctica on land.
Courtesy Ski Antarctica
Sailing offers another take on the Antarctic, a throwback to the days when ships powered by canvas were the only way to reach and explore the frozen continent.
"For me, exploring Antarctica by private yacht is the only way to truly experience the wonder of this great white wilderness," says Colby Brokvist, who leads Antarctic sailing trips for Colorado-based Natural Habitat Adventures.
"My favorite part of these trips is the intimacy we enjoy. Antarctica is the greatest wilderness on our planet and -- with the support of our expedition yacht -- we spend quality time within immense, peaceful landscapes and among throngs of marine wildlife. For those who seek true immersion in the wildness of Antarctica, this is your trip."
If you opt for cruising the Antarctic on a larger ship, but prefer true adventure to posh pampering, expedition leader Michael Ginzburg of Oceanwide Expeditions suggests choosing a journey with a flexible itinerary that allows the captain and crew to engage in a little exploration along the way.
On Ginzburg's last cruise of the 2018-19 season, a late March voyage aboard Oceanwide's MV Ortelius, the ship was able to sail beneath the Antarctic Circle (66°33 south of the Equator) and visit three places where the crew had never previously been.
Ginzburg was especially excited about being able to sail through The Gullet, a narrow, normally ice-bound and glacier-clogged passage between Adelaide Island and Graham Land.
"In more than a decade down here, I've only done it once before," says Ginzburg. "And that was a Russian research ship, not a passenger vessel."
Read on to discover 11 adventurous ways to discover the Antarctic.
Scuba diving and snorkeling
A totally waterproof drysuit is an absolute must for diving in the Southern Ocean.
Alexander Kassler/Oceanwide Expeditions
Venturing into the super-chilly liquid of the Southern Ocean requires previous experience with cold-water diving and top-notch equipment, especially a totally waterproof drysuit.
But the rewards are incredible: a chance to explore the underside of icebergs, swim with leopard seals and probe historic wrecks.
LiveAboard.com offers trips on four different Antarctic vessels that offer scuba and snorkel.
Taking to the slopes in the Antarctic means schlepping yourself and your equipment up every single mountain. Nearly all of the downhill involves peaks on the Antarctic Peninsula, some of which are doable as day trips from your ship and other requiring a multi-day sled journey and establishing a base camp.
Ski Antarctica has several choices, including a month-long journey aboard the yacht Icebird that includes 18 days of ski mountaineering on the peninsula.
Like the polar explorers of old, cross-country skiing to the geographic South Pole involves crossing ice shelves, glaciers and the massive West Antarctic Ice Sheet, while towing a sled full of equipment and supplies behind you the entire way.
If that sounds like your kind of thing, Antarctic Logistics & Expeditions organizes several expedition trips each southern hemisphere summer, ranging from 12 days to two months.
Pitching a tent is another up-close way to experience the frozen continent.
Ignacio Marino/Oceanwide Expeditions
Just about any mountaineering or climbing or long-distance skiing in the Antarctic involves camping.
But you don't have to be a super athlete to snuggle up in a tent on the continent overnight. Oceanwide Expeditions has created Basecamp Adventure Cruises with a range of outdoor sports activities (kayaking, snowshoeing, hiking and soft climbing) as well as a camping night away from the mother ship.
But for those who really want to paddle between icebergs, penguins and whales in a small plastic boat, Southern Sea Ventures is launching a new program for the 2019-2020 season that includes five to seven days of kayaking, depending on prevailing sea and weather conditions.
In days gone by, only research and military aircraft were allowed to land in the Antarctic.
But in recent years, several companies have pioneered day trip and single overnight flights to the continent including DAP Airlines from Punta Arenas in southern Chile and White Desert from Cape Town, South Africa.
Sailing offers opportunites to explore areas where larger ships won't fit.
Ben Wallis/Natural Habitat Adventures
Another throwback to the golden age of polar expedition, sailing across the Drake Passage to the Antarctic offers a quieter, less crowded way to cruise the Southern Ocean, as well as opportunities to explore bays and channels where larger ships can't fit.
Natural Habitat Adventures offers a 17-day private yacht expedition aboard a vessel that takes no more than seven passengers. With a special permit from the National Science Foundation, the itinerary includes a number of shore landings and three overnights on the peninsula.
For those trying to conquer the highest peak on each continent, the 16,050-foot (4,892-meter) Mount Vinson is the peak they're after in the Antarctic.
Although extremely strenuous, the Vinson ascent is not especially technical, involving a traverse of gentle glaciers and 45-degree, snow-covered slopes.
Antarctic Logistics & Expeditions offers 12-day Vinson climbs as well as guided ascents of 14,058-foot (4,285-meter) Mount Sidley -- Antarctica's highest volcano, one of the Volcanic Seven Summits and one of the world's most remote climbs of any kind.
Run since 2006 on snow and ice -- at temperatures that can reach -20 degrees Celsius with strong winds -- the runs play out at the foot of the Ellsworth Mountains. All competitors are flown in from Punta Arenas, Chile, using a huge transport plane.
Vivid blue frozen passages create an otherworldly landscape.
Courtesy White Desert
The massive ice shelves and glaciers of Antarctica are rife with spectacular caves and tunnels carved into ice formed thousands of years ago.
These subterranean worlds -- often lit by magical bluish light -- offer a totally different take on polar nature. White Desert offers guided ice caving as one of several land-based activities at its remote Whichaway Camp in Queen Maud Land.
Real expedition cruises
For those who crave real adventure, seek out a company or ship that offers more than just Zodiac rides -- activities like hiking, kayaking, scuba diving or other less sedentary activities.
Michael Ginzburg of Oceanwide recommends booking passage on the first voyage of a given season -- when the sea ice isn't completely melted yet -- or the last journey of the season when ships can cruise farther south because the floe ice hasn't started to re-form.