Block off six months on your calendar for a round-the-world trip aboard Oceania Cruises' luxurious line, whose staterooms are furnished with gleaming teak and neoclassical design.

As you sail from Miami, you'll make landfall on five continents before you arrive back in Miami. That's everywhere but Europe and Antarctica, touching down for a series of extraordinary shore excursions.

Head to shore in Namibia for an off-road safari across the otherworldly Namib Desert, then paddle an out-rigger canoe along the lush, tropical coast of Bora Bora. Your home for half the year is the ship Insignia, which accommodates up to 684 passengers and comes equipped with a ship's library, a well-stocked wine cellar, a putting green and an artists' studio.

The Insignia departs on one circumnavigation each year, with fares for the round-the-world adventure from $35,000 per person (double occupancy).

Slide behind the wheel of a brand-new Porsche Cayenne for a series of Porsche-curated trips that concludes with a spectacular drive from Bangkok into the Himalayas.

While the Porsche Travel Club organizes regular driving tours throughout the world, Porsche says the Porsche World Expedition is an adventure that will only happen just once, ever, from May through October of 2018. Drivers can opt in for one section, choosing between routes across Australia, Africa, South America, Europe, Central America and Southeast Asia, or make it a single epic drive that spans more than five months.

And while a convoy of Porsches is guaranteed to turn a few heads, not all traffic stops for travelers. As you drive from Johannesburg to the Serengeti National Park, you'll witness Africa's Great Migration, the wildebeests' thunderous voyage between seasonal ranges. (Prices available upon request.)

Step into the golden age of rail travel while looping the world on a 23,000-mile journey by Great Rail Journeys that combines some of the world's most iconic train trips.

Scenery is the real draw, but the trains are just as magnificent. The second half of the trip includes time on The Tsar's Gold, a sumptuous private train that follows the Trans-Siberian railway across Russia, as well as a trip aboard the Venice Simplon-Orient Express from Venice to London, in cars decked in gleaming wood, crystal and Art Deco detailing. Great Rail Journeys offers this round-the-world trip once a year, with prices from £24,495 (about $32,000) per person.

Traveling by cargo ship isn't everyone's idea of luxury, but there's an undeniable romance to following the oceans' quiet highways.

Circumnavigate the globe with Maris Freighter Travel Club Int'l and you'll pass through the Suez Canal and the Panama Canal, engineering marvels that transformed the modern world.

You'll have day after day to watch the sea and sky after setting sail from the global shipping hub of Houston, Texas, then arcing across the Atlantic Ocean towards North Africa. Passengers take simple meals with the ship's crew, and onboard cabin stewards tend to the basic suites, which include private bathrooms and small sitting areas. All cabins have exterior windows, but while side-facing suites gaze across the ocean, front-facing rooms look out on decks piled high with colorful shipping containers.

The introduction of shipping containers has vastly reduced the number of crew, and most freighters can accommodate a maximum of 12 passengers, so travelers will enjoy these expansive views far from tourist crowds—or any crowds at all. Eastbound round-the-world cruises organized by Maris Freighter Cruises depart every few weeks and take 77 days, with prices from €100 a day (about $118).

The luxury of high-end bikes meets a truly rugged adventure on the Around the World Expedition from Edelweiss Bike Travel, an Austria-based company with a fleet of Ducatis, Triumphs, BMWs and Royal Enfields.

Riders mix and match a series of eight routes that range from 33 to 80 days, or go all-in for an epic journey that adds up to 429 days on the road.

Each segment is the ride of a lifetime. With a support vehicle to haul your bags, you'll trace a route from Los Angeles to Panama City, Cape Town to Dar es Salaam then Istanbul to Bangkok, testing your stamina and endurance in the mountains of Kyrgyzstan, the vast Bolivian salt flats or the lush jungle that covers the island of Sumatra.

And while the route is carefully planned in advance, travelers have the freedom to pick their own roads, rejoining the group each night to share share riding stories over German beers or Chilean wine. Segments range from €9,500 to €29,000 (about $11,000 to $34,000).

The world's largest research museum hits the road in style, aboard a private jet that's outfitted with two-by-two leather seats.

In keeping with the Smithsonian's focus on science and culture, you'll be accompanied by a top conservationist as you loop the world in 24 days, touching down everywhere from Machu Picchu to the Serengeti.

Since stops include some of the world's undisputed wonders, you can compare the Taj Majal's marble architecture with the magnificent temples at Angkor Wat, snorkel the Great Barrier Reef then stand at the foot of Easter Island's enigmatic moai. Prices for the private jet adventure, which seats just 80 passengers, start at $82,950.

If ready-made tours seem too off-the-shelf, the legacy travel company Abercrombie and Kent designs custom adventures that can stretch across the globe.

Opt for a tailor-made journey, and you'll be exploring with a local guide, discovering every continent through your very own lens.

The experience can be as luxe or rugged as you choose, with travel by charter flight, river cruiser, camel or private train car.

Combine them all and you could loop the world, pausing for a full cultural immersion in a traditional Maasai village, or to check birds off your life list while crossing Botswana's Okavango Delta.