(CNN) — First, some comforting reassurance to all panicked late 20-somethings fighting off enough unchecked lists already. This isn't really a checklist, and 30 is really just a number. So if you're 72 and don't feel a day over 29 ½, the following naturally applies to you as well.

Just two suggestions if you haven't done some version of these open-ended "must do" experiences before you turn "30."

1. Approach the following with a healthy dose of imagination, caution and wild abandon.

2. Get started:

1. Travel solo

Travel is a social endeavor. So why do it alone? For that very reason.

What greater incentive to meet new people, hang with locals, compare notes with fellow travelers and turn a world full of strangers into new friends when the alternative is to retreat to your Rick Steve's guidebook or converse with the empty train seat beside you?

Traveling alone is courageous. It's also convenient. Stop, go, stay, leave without a group vote. It's comfortable -- guess who gets the better seat? And uncomfortable -- guess who has to leave their safe place and make it happen?

Most importantly, traveling alone gives you a chance to spend some quality time with that special someone just yearning to get to know you better -- you.

2. Climb a mountain

Japan's Mount Fuji is a great place to start your climb-a-mountain assignment. Shutterstock

Yes, you'll probably need to be in decent shape.

No, you won't need supplemental oxygen, a small fortune, a team of sherpas and a revised life insurance policy to plant your flag on your own doable version of Everest.

Mount Kilimanjaro (Africa's highest peak), Mount Fuji (Japan's), Mount Elbrus (Europe's), Mount Whitney (U.S. Lower 48's), Pico de Orizaba (Mexico's) and scores of other superlative walk-up mountains around the globe are sufficiently challenging and bucket-listable for the rest of us.

So is any captivating, less-famous peak with a safe, well-maintained trail that leads to the very same place: The top of the world.

3. Take a classic train ride

Carving its own path between giant peaks. Through blasted-out tunnels. Across trestled rivers. Rolling, mile after mile, without the distraction of a steering wheel or "mild turbulence" warnings from the captain.

In a world possessed by planes and automobiles, there's still nothing quite like a great train ride.

Whether it's in a Great Dome Car on Amtrak's Adirondack route during the height of fall foliage season in Upstate New York aboard Mexico's spirited Tequila Express from Guadalajara to Amititán or through eight time zones on the Trans-Siberian Express, no other conveyance ties us to our planet's myriad shades and sheer size like the iron horse.

4. Browse through a market

You can browse for fish, fabrics and figurines anywhere.

Entering the souk-maze of Marrakech , Istanbul's Grand Bazaar, Cairo's Khan el-Khalili or Old Delhi's Chandni Chowk isn't ultimately about any of those things. It's about people. And all the colorful chaos that comes with them in places like this. Some other places to think about:

-- Thailand's floating markets.

-- Holland's flower markets.

-- Tokyo's tuna markets.

-- Argentina's antiques markets.

-- Pasadena's Sunday flea market at the Rose Bowl. The list can go on and on.

Choose your own random human encounters and sensory overload. Then go ahead, wear the invisible tourist badge and acquire lots of stuff you don't really need. No beige pants and money belt required.

5. Trek an epic trail

Fastening your waist belt. Snapping your sternum strap. Taking a deep breath of real air at the trailhead.

Performing your greatest disappearing act for untold days or weeks. Nothing hanging over you but sun, moon, stars, spectacular scenery and spare packs of dried ramen.

For some, the voluntary act of hoofing across miles of pristine backcountry in the vaguely present company of bears, javelinas and the odd roaming mountain lion is a no-go. For others, it's the long-awaited walk of a lifetime. If you're in the latter camp, the first challenge is choosing the perfect walkabout from a world's supply of epic options, near and far.

They range from Peru's famous Inca Trail with its Machu Picchu payoff to California's John Muir Trail, featuring over 210 miles of prime Sierra Nevada mountain backcountry between Yosemite and Sequoia National Parks.

You can walk across an entire country on England's C2C Trail (190 rugged green miles from Irish Sea to North Sea) or whet the knee joints along New Zealand's famously stunning, 33.2-mile Milford Track.

Wherever you go, in no time it all starts to make perfect, life-affirming, shoulder-incinerating sense.

6. Visit where your great-great-great grandparents grew up

If your family has lived in the same house for the past six generations, you're done. If you have a coat of arms traceable to a village on the Isle of Man, you're halfway there.

If you haven't a clue where any of your umpteen great-great-great-grandparents grew up, you have some adventurous charting to do. And, no, "Somewhere near Brazil" or "Basically Central Asia" doesn't count.

C'mon people. These are our hallowed forebears. They were around before "Moby Dick" was published. They bequeathed their nose to you and their facility with numbers to your future twin great-granddaughters.

The least we can all do is adventurously traipse to those arbitrary coordinates -- Minsk, Famagusta -- where you never expected to say "these are my roots."

7. Learn a language

Why bother when you failed 11th-grade Tagalog, you're a gifted pantomime artist and you'll only be going to Manila for a week? The excuses for not picking up a new language grow exponentially as we do. And so do the reasons for taking a little time to master (or just muster) a few useful (or charmingly useless) phrases in some other tongue.

Like doing crosswords, learning a new language is good for your brain (they say). More importantly, dour-faced, tourist-fatigued locals everywhere may even smile for your honest efforts.

8. Watch a game in a famous stadium

See the Sox at Fenway in Boston, Major League Baseball's oldest stadium (b. 1912). FC Barcelona at Camp Nou, Europe's largest stadium (99,354 people). The Calgary Flames at the Scotiabank Saddledome, western Canada's greatest homage to hockey and giant saddles.

There are so many possibilities: Wembley, Wrigley, Estadio Azteca, Kaohsiung National, Melbourne Cricket Ground, Sapporo Dome and on and on. Even if you couldn't care less who's playing, winning or which sport it is, half the fun is high-fiving frenzied strangers who do.

9. Change the world -- volunteer abroad

There's a special place (several, actually) for free-spirited travelers who place signing on for a stretch of international volunteer work above, say, running with the bulls. The list of charitable organizations allowing you to lend a hand to a world's supply of worthy causes is long. And the geographic possibilities are just as wide.

Options range from staple orgs such as Habitat for Humanity operating in all 50 U.S. states and nearly 100 other countries, to the Peace Corps , which offers some shorter programs than the usual two-year stint.

Projects Abroad is designed specifically for grads and professionals on a career break. Global Vision International offers a range of over 150 volunteer abroad projects up to six months long.

Volunteering with a solid program won't just change your life but other lives, too.

10. Cross a border on skis, bicycles, zip line, etc.

Any traveler can enter another country through an airport, train station or bus terminal. Much less perfunctory: crossing a border practically any other way:

-- On skis with an international pass between Zermatt, Switzerland, and Cervinia, Italy, under the crest of the Matterhorn.

-- Or zip line between Andalucia, Spain, and Algarve, Portugal.

-- In a water taxi from southern Belize to coastal Guatemala.

-- Or a bicycle between Glacier National Park and southern Alberta.

Remember your passport just to keep things friendly and fun.

11. Stay at a hostel and make some friends

The mattresses aren't Four Seasons quality, and there will be no Aveda products in the communal bathroom. But there are other perks at the cheapest communal flophouse: a complimentary set of new travel buds you'd never meet at some sterile hotel.

Ever since 1912, when a German schoolteacher hatched a plan to create the first youth hostel (originally for school kids to have a clean, affordable, communal place to stay on class trips), the concept has evolved into the backpacking backbone for "youth" of all ages.

Today, Hostelling International tallies thousands of official HI hostels in more than 80 countries, and the industry has spawned many more independent joints wherever backpackers congregate -- plus new terms such as boutique hostel, 5-star hostel and mobile hostel.

The best amenity at all of them: A comforting sense that the planet isn't that lonely after all.

12. Take a cooking course abroad

Give a traveler a Sichuan catfish and you feed her for a day.

Teach her how to make fresh-made pasta in Italy, perfect dumplings in Shanghai, beef-and-Guinness casserole in Ireland, or authentic southern barbecue in North Carolina at a fun, informal cooking class, and she has several to-go boxes.

Plus an exotic, hands-on culinary experience and some badly needed new recipes to bring home.

13. See amazing animals in the wild

There's no match for seeing a majestic creature in the wild. Shutterstock

Head to Brazil's Pantanal region -- one of the world's largest inland wetlands and last strongholds of the largest cat in the Americas -- and join one of numerous wildlife outfitters who'll happily help you find wild jaguars. And there are bonus animals: hyacinth macaws, capybaras and caimans lounging in their natural habitat.

Same goes for grizzlies and bighorn sheep in Glacier National Park. Royal Bengal tigers and sloth bears in India's Kanha National Park. Chimps and gorillas in Uganda. Lemurs in Madagascar.

Close encounters with wild, often endangered animals in their actual homes imprints on more than just our zoom lens. It serves that greater, crucial reminder -- that we're all in this together.

14. Sample a wine country that's not Napa or Burgundy

Why voyage to some distant town hiding on the bottom of Africa, the far side of the Adriatic, or the foot of the Andes and beyond to drink wine that will often enough gladly come to you? For the same reason we wine hop through those must-sip spots in California and France.

It's not just about what's in the glass, but what's swirling out there all around you. Sometimes way out there. Mendoza, Argentina. Dubrovnik, Croatia. Walla Walla, Washington. Cape Town.

These and other farther-flung wine regions confirm what we've always suspected. Great wines can transport us. Literally.

15. Have a one-of-a-kind aquatic experience

Millions of benign jellyfish fill a marine lake in the Republic of Palau. Shutterstock

Water. It's everywhere. Covering 71% of the planet. Comprising at least 60% of our bodies. Supporting an entire whale-watching industry. Is there anything we can say about water that would further enhance your appreciation of this stuff?

Possibly, if you haven't had a truly off-the-deep-end waterborne experience yet.

Like, for example, peacefully and painlessly basking in a lake full of jellyfish in the Rock Islands of Palau. This is where millions of benign Mastigias papua etpisoni ("golden jellyfish") draw thousands of day-trip visitors to Jellyfish Lake from nearby Koror.

Or snorkeling with salmon on Vancouver Island's Campbell River where visitors can float past schools of pink, coho, Chinook and sockeye salmon making their amazing journey upstream during the heart of the salmon run.

16. Go to a wild and crazy party or festival

Just because you're only young once, it doesn't mean you have to experience Burning Man, attend a Full Moon Party or get pummeled with ripe tomatoes at late August's La Tomatina Festival in Buñol, Spain . But in a world full of one-of-a-kind life celebrations, there's a perfect one out there for each and every one of us.

Best done before you risk running into your kids at one of them.

17. Be a game show contestant

Many a game show has come and gone since 1972, but thankfully you can still be a contestant on "The Price Is Right."

The longest running, single-network game show in television history has been a mainstay on the CBS daytime grid for 45 years. Tickets are free and technically any prescreened audience member could be the next contestant to "Come on down!"

If it isn't you, hundreds more seats need filling at all of those other shows taped before a live audience in Los Angeles, where you can see first-hand how these masterworks get cranked out while perfecting your best canned laugh.

Or, for a behind the scenes look at Hollywood's most hallowed dream factories without all the endless takes, VIP tours at the Warner Brothers Lot and Universal Studios whisk guests around the lot (for a price) without a line or a lookie-loo crowd in sight.

18. Ride a famous subway

London's subway signage is known around the world. Shutterstock

Here's your long-awaited opportunity to "mind the gap" in London, take the "A Train" in New York, visit all 300 stations on Paris's 16-line Métro, or approach a stranger in Moscow and ask that burning question: "How do I get to Preobrazhenskayaploshchad Station."

Don't overlook those also-running subway towns. Los Angeles is home to a handsome pair of Red and Purple Lines that most residents don't even know about. Tashkent, Uzbekistan features one of the world's most ornate undergrounds along 29 stations decked in glass, granite, marble and carved alabaster -- all designed by prominent artists and architects.

19. Double down in Deadwood or Monte Carlo or Vegas

Step past the golden fountains of Las Vegas' Bellagio, through the lion-sculptured lobby into that tireless golden-hued room of cruddy odds.

Go up the stairs of the fabled Casino de Monte-Carlo, past the dubious, square-shouldered Monégasque doorman, through the marble atrium and into the chip-snatching jaws of the frescoed, chandeliered Salle Europe.

Strut down Main Street in Deadwood, South Dakota past a commemorative No. 10 Saloon where Wild Bill Hickok once mused over his final poker hand and into the awaiting Three Card and Blackjack tables at the Gold Dust, Midnight Star and Mineral Palace.

Even if you're at the cheap table, it still counts.

20. Ride a horse -- or some other sturdy animal

Seeing any place from a saddle changes your whole perspective: On the beach in Costa Rica. At a dude ranch in New Mexico. On the Mongolian Steppe. At the nearest stable to your house.

And there's a range of animals ready to transport you:



-- Explore

-- Ride a camel through Timanfaya National Park in Lanzarote, Canary Islands.

-- Take a yak fpr a spin in the Mongolian Gobi.

-- And, apparently, you can ride an ostrich a la "Swiss Family Robinson" in Oudtshoorn, South Africa. -- Descend into the Grand Canyon on a sure-footed mule.-- Explore Chiang Rai, Thailand, on a willing elephant -- Ride a camel through Timanfaya National Park in Lanzarote, Canary Islands.-- Take a yak fpr a spin in the Mongolian Gobi.-- And, apparently, you can ride an ostrich a la "Swiss Family Robinson" in Oudtshoorn, South Africa.

21. Eat a hot dog in Times Square

If you'd rather eat a giant spider than a hot dog on a busy street corner, the option is open to you -- along with all those other classic street food choices:

Hot, warm, soft pretzels in Philadelphia. Falafel in Beirut, Haifa or Cairo. Arepas in Cartagena. Pani puri in Mumbai. Simit bread ring in Istanbul. Deep-fried tarantula on a stick in Phnom Penh

Whatever open-air munchie appeals to your taste buds and gastrointestinal courage, down the hatch.

22. Drive a magnificent coast

Few roads are as spectacular as California's Pacific Coast Highway at Big Sur. Shutterstock

Close your eyes and imagine these stunning coastal drives:

Maybe you drive from Naples to Amalfi with the wind in your hair and the Mediterranean a single perilous hairpin away. Go from Cape Town to Hermanus along South Africa's rugged Western Cape. For something really off the radar, there's Iquique to Antofagasta along Chile's Ruta 1.

And there's a host of others:



-- Canada's Cabot Trail.

-- Corsica's D81.

-- Croatia's Adriatic Highway.

-- Australia's Captain Cook Highway.

-- -- California's Big Sur.-- Canada's Cabot Trail.-- Corsica's D81.-- Croatia's Adriatic Highway.-- Australia's Captain Cook Highway.-- Florida's connect-the-Keys Overseas Highway

Unless you're in Bolivia or Saskatchewan, finding a stretch of life-affirming shoreline to drive beside shouldn't be too hard in a world with this much coastline.

23. Hail a New York taxi or a London cab

Paying to much for a canary yellow taxi in Manhattan during rush hour or shelling out £80 for a ride from Heathrow to central London in a black sedan may not seem logical when you can shave that bill to a low fraction with the tap of an app.

Take the ride anyway. Tip well. Pay in cash. The fast-fading old world thanks you for it.

24. Walk across a famous bridge

San Francisco's Golden Gate Bridge is among the world's most identifiable. Shutterstock

With some bridges -- such as China's 102.4-mile Danyang-Kunshan Grand Bridge (part of the Beijing-Shanghai High-Speed Railway) -- you may prefer to experience on a very fast train.

With others -- such as Switzerland's just-opened Charles Kuonen Suspension Bridge , a 1,621-foot-long span with 279 feet of alpine country air wafting below your hiking boots -- you may want to be honest with yourself before you try to cross.

That still leaves hundreds of spectacular bridges to marvel upon on foot at the right pace.

Drivable icons such as San Francisco's Golden Gate, Sydney's Harbour Bridge, New York's Brooklyn Bridge and Budapest's Széchenyi Chain Bridge are too important to unceremoniously whiz across in a car. And then there are pedestrian-only crossings such as Florence's Ponte Vecchio and London's Millennium Bridge you'll want to consider.

25. See a live volcano

Witnessing a smoldering portal into the Earth's soft center up close is both a thrilling and sobering reminder that our planet isn't filled with the sweet, creamy nougat we thought.

"A thousand branching streams of liquid and gorgeously brilliant fire ... like a colossal railroad map of the State of Massachusetts done in chain lightning on a midnight sky," is how a young Mark Twain described an erupting Kilauea volcano in Hawaii in 1866.

Expecting an anticlimax, the writer of course was blown away.

As are today's visitors to Hawaii Volcanoes National Park, Italy's Stromboli, Etna and Vesuvius. Costa Rica's Mount Arenal. Iceland's Eyjafjallajökull, Indonesia's Merapi, DRC's Nyiragongo and other alluring volcano sites -- all best approached with sound risk assessment and a knowledgeable guide.

26. Visit the observation deck of a skyscraper

First it was the Washington Monument. Back in the 1880s, D.C.'s namesake edifice ruled the skies with the world's loftiest observation deck -- an amazing 499 feet high. Until Paris's Eiffel Tower owned the highest perch (905 feet) for the next 42 years.

Then came New York's Empire State Building, with views across four state lines. That was bested in the 1970s by New York's Two World Trade Center, then Chicago's Willis Tower, then Toronto's CN Tower with its unsurpassable 1,467-foot-high Space Deck (now SkyPod).

Then came this past decade, which saw an onslaught of record-breaking towers overlooking Shanghai (Shanghai World Financial Center), Guangzhou (Canton Tower) and Dubai -- home to the current 1,841-foot observation deck record-setter in the Burj Khalifa

The tallest projected viewing deck is expected to hit the 2,080-foot mark in the upper reaches of Saudi Arabia's 3,280-foot colossus, Jeddah Tower, in 2019 -- though we still suggest you start with the Washington Monument and take it all in stride.

27. Enter a real castle

California's Hearst estate, Florida's Ca d'Zan and North Carolina's Biltmore all count as castles in their own young Gilded way. But for the real-deal, iconic stone domicile where kings and countesses slept back when suits were made of metal and pillows from very small pebbles, you'll have to cross an ocean and other drawbridges.

And pick your country -- because there are so many spectacular castles, all rife with colorful histories, colorless turrets and so-12th-century plumbing.

There's Scotland's Edinburgh Castle. Wales' Raglan Castle. Ireland's Blarney. England's Warwick, Leeds, Windsor and Bodiam -- just to name a few favorites from those parts.

There's Germany's Burg Frankenstein. Portugal's Palácio da Pena. Prague's Prague Castle. Japan's Himeji Castle. And don't get us started on France and Transylvania.

Like Florentine churches, you can overdo it. Pick one or two castles to visit (three at most). And, please, no Monty Python reenactments.

28. Attend a rodeo

Cheyenne Frontier Days in Wyoming happens in July. Shutterstock

Yes, you can pull off a cowboy hat and matching boots. You just need to be in the right place at the right time with the right bronc riding, barrel racing, steer wrestling, team roping lovin' crowd.

Virtually any U.S. state west of the Mississippi will point you to its vote for the "daddy of 'em all in the rodeo capital of the world."

Annual contenders include:

-- Wyoming's Cheyenne Frontier Days (late July)

-- Texas' Fort Worth Stock Show & Rodeo (January 12 - February 3)

-- Oregon's Pendleton Roundup (September 13-16)

-- Kansas' Dodge City Roundup (early August)

-- Arizona's Prescott Frontier Days (June)

-- Colorado's Durango Fiesta Days (late July).

Outside the United States, Canada's 105-year-old classic Calgary Stampede (July), Brazil's Festa do Peão de Boiadeiro de Barretos (August 17-27) and ÉquiBlues in Saint-Agrève, France, prove cowboys know no borders.

29. Leave the guidebook at home

Thanks to a multimillion dollar industry serving our need to know absolutely "everything" about a place before arriving, we never have to be without the Top 10 bars in Chicago at our fingertips.

Just for kicks, try this next time. Leave your dog-eared Rough Guide and Yelp reflexes at home. Just go. Follow your own footsteps. Give your own intrinsic travel smarts room to surface. Let the Monsoon take you where we want travel to take us at its core. Into the greater unknown.

30. Get a massage in an airport

If there's one thing on this list you need to do as soon as possible, even if you're not actually flying anywhere, start here.

If there's a more important place than a jammed international airport to relieve stress and boost an against-all-odds feeling of wellness, we haven't been there.

It's no secret (at leat among premium class passengers) that major airline hubs now offer a lineup of spa services in their private lounges and clubhouses -- facials, hot stone treatments and cooling leg rubs in quiet rooms piped with ethereal tunes beyond all the plebeian gate noise.