You are a traveler, bound to catch the evening ferry to the Isle of Skye in Scotland’s Hebrides islands. A half-day’s steady thrum from a nameless diesel engine out of Glasgow’s Queen Street station lulled you into a dull stupor well before you pulled into Fort William’s Tom-na-Faire Depot. From there it’s still an hour’s journey yet to the Mallaig Ferry Terminal.

But at the depot you transferred to a new train, pulled by The Great Marquess herself. And so for the breathtaking stretch along the northern banks of Loch Eil, instead of rude horn blasts at every crossing you’ve heard the melodious toot of her steam whistle punctuating your click-clack passage over the rail seams.

Now you’re being carried one hundred feet above the River Finnan. You open the sash window and lean out, looking back at the tail of the train smoothly rounding the curve. What a graceful way to traverse the West Highlands toward a night of Hebridean dreams.

I always enjoyed going home during college breaks. My dorm was fine, but my parents’ house would always be Home -- or so I thought until I grew up, they moved, and I made a home of my own. In the dining hall before one spring break, I asked a new German friend if she had any vacation plans. “I’m seeing family near Koblenz.” “Oh,” I said, “I’ve been! Do you know the lovely castle?” “Ah yes,” she said, a warm smile splitting her handsome face, “that’s Papa’s house. You must visit us!”

You’re headed home after years abroad. It will be wonderful to sleep in your old bed. It’s been so long you check a map at the tricky turns. But then you’re there, perched on a promontory in an oxbow of the Elz. For thirty-something generations, this has been your family’s home.

Now to find your room among the hundred spread around eight timber-framed towers. Past the Knights’ Hall with its jesters’ heads and the armory full of crossbows and halberds. You mistakenly open Countess Agnes’ door, retreating as her ghost recounts yet again her bravery under siege. In your own room, at last, you curl up on a bearskin rug.

You leave Geneva, aiming for tiny Liechtenstein by nightfall. Via Bern it’s only four hours. But an Alpine road is its own destination. So you turn south around lac Léman, skirting the French and Italian borders. Châteaux cap every foothill. The Matterhorn is just one of myriad cloud-obscured peaks. You packed snacks, but dry Landjäeger sausage and chewy Gummibärchen can only tide you over for so long.

You spot a hotel nestled in the crook of a hairpin turn. Parked cars suggest interesting guests: a silver Aston Martin, a black and yellow Rolls-Royce, a white Mustang convertible. Rhône Glacier’s blue tongue winds down the gorge. It once reached here, but over a warming century receded a mile. You’re curious to see the ice grotto, a hundred-meter tunnel of enchanted azure light fit for a Tibetan Yeti. But first food!

Rösti potato pancakes? Älplermagronen, the local mac and cheese? Bread dipped in gooey Gruyère? Of course some rich Swiss chocolate. You settle in for the night, already imagining the breakfast spread.

Manhattan’s skyscrapered canyons slice the sky into sections. Each day of the year, the sun sets behind a different building. Each day, that is, except two in midsummer straddling the solstice, when the sun settles on the horizon in line with the City’s tilted grid and its gilding light stretches the full breadth of the island.

You’re standing on the Tudor City Bridge. Over your right shoulder, the UN building, that shiny slab of peaceful dreams, stands between you and Queens. The day’s last rays cast the length of 42nd Street in molten gold. Past the Chrysler Building and Grand Central, past lions Patience and Fortitude guarding the Public Library, the sun dips into the Hudson like a commuter entering the Lincoln Tunnel.

The City never sleeps. But for this golden moment the bustle pauses. Everyone matches your westward gaze, gratefully receiving a solar blessing. Thus illuminated, the concrete jungle disappears, Gotham transformed to El Dorado, every stranger just a friend not yet met.

The air is different in Bhutan, 10000 feet above sea level. Taktsang Monastery is built into a cliff. The Precious Guru Padmasambhava first flew here on an enchanted tigress. Your trek begins beside a water-powered prayer wheel. Then it’s up and up stone stairs and blue pine-lined trails toward a cloud-shrouded destination. If you reach the temple, it’s a dizzying 3000 foot drop to the Paro Valley. Why even bother? If only you could ask the Buddhist master’s wife, the Fairy of Wisdom, to hail a flying tiger. But we can’t wish our way to the Green World. Every rugged step is a meditation. The journey is the point.

You focus on distant chimes and the sound of a waterfall plunging to a sacred pool. Your path is festooned with moss and colorful flapping flags. Even in this remote holy spot, each breeze is a reminder that everything is connected. The atoms in every breath have circled the globe. The Himalayan rhododendrons here have Appalachian cousins. You continue upward as your previously obscured goal is revealed.

Perhaps no place more closely associates with the Green World than the land of the leprechaun. Eirinn. Inis Fail. The Emerald Isle.

Kindly locals at the country’s southern edge direct you to “Cove.” Cross Belvelly Bridge to the Great Island of Cork Harbor till you see the cathedral’s eight-sided spire, rising higher than any other in Ireland. The last sound heard by brave millions sailing from here to America -- or a fateful encounter with an iceberg or U-boat -- may well have been the toll of St. Colman, most massive of the carillon’s 49 bells. Beside the flying buttresses and traceried parapets, look out over Spike and Haulbowline -- Ireland’s Alcatraz and island of foxes -- then turn around and admire the brilliant prismatic town.

This row of Victorians -- Cobh’s “deck of cards” -- spans the spectrum. What if this rainbow IS the pot of gold? Consider as you dream: What fairy wouldn’t trade a golden hoard to revel amidst Cobhians’ lively reels and thrilling tales of welding great steel-ribbed ships?

From the Chrysler Building’s shadow you walk up Lexington, under the Graybar Passage’s chandeliered arches, into the Main Concourse’s marble-clad, celestial-ceilinged bustle. Light pours in. Crowds or no, you feel the freedom of tremendous space in this Beaux-Arts poem in stone. This granite edifice, too grand to hide mere pixies among its sculpted acorns and oak leaves, instead hosts mighty Mercury, Hercules, and Minerva, personifying the accomplishment of speed, strength, and intellect that is the world’s largest train station.

This is a shore formed of steel and stone where waves of new travelers roll in every minute. Every sort of character passes through. In the whispering gallery you may meet anyone coming up from the Oyster Bar: Roger Thornhill, Nick and Nora, Holden Caulfield, Clark Kent.

Buy a ticket for your dream train. Fancy the Sunset Limited, Zephyr, or Niagara Rainbow? Check the departures board and your watch against the Opal Clock. Find the ramp to your platform and embark.

You silently stand beneath the barrel-vaulted ceiling of a station from which you can embark to two hundred thousand destinations, each waiting to be rediscovered within the covers of an old book.

Only a fool would try to name the world’s greatest book. But as for the most lovely . . . it would not be so foolish to place that crown on the Book of Kells whose brilliantly illuminated pages live here.

In the Green World, Brian Boru’s harp doesn’t just sit in its thick-walled case but rises, ancient melodies stirring its brass strings.

The Long Room is lined with busts of great minds from centuries past. Should they come alive, animated with their inspirations’ spirits, with whom would you choose to chat? Newton? Aristotle?

Stroll with Jonathan Swift. Do you dare to adventure where his Gulliver traveled? Here in this hall redolent of biblichor, breathe in that blend of old paper and ink, open a volume, and set forth.

Sandwiched by Spring Street and Houston, on a block now considered SoHo but not so long ago solidly part of Greenwich Village, stands a green storefront full of golden loaves. Between exposed brick walls and under frosted Art Deco light fixtures hanging from a white tin ceiling, a coal-fired oven has turned out Italian pepper biscuits, perfectly crisp breadsticks, and dense stirato baguettes since 1920.

Across cultures, with a nearly infinite variety of crusts and crumbs, bread is a universal small, good thing. Everyone recognizes the pure wafting joy that is the delicious wisp of steam escaping a shared loaf.

Tonight that warm exhalation, the spirit guiding you, is Anthony Dapolito, born the same year as his parents’ bakery. Dark eyes flash behind thick glasses above a warm smile. A calm, genial, confident presence. The soul and unofficial Mayor of the Village. A true public servant. His gravelly voice recounts tales of the old neighborhood. He hands you a warm roll, says, “Life is a great, beautiful accident.” Pointing to your heart he solemnly pronounces, “You are rich in here.”

We typically picture the Green World solely composed of snug forest glens, perhaps alight with fairies. But it encompasses anywhere you might visit in a dream, dense cityscapes as well as country idylls.

A double-barreled portal traverses the East River, a unique domain in its own right -- not a true river but a drowned valley lined with Inwood marble, a classy tidal dancehall for urban seafolk. To pass through the Brooklyn Bridge’s neo-Gothic arches is to move between boroughs, between worlds. By foot, bike, or car, it takes you places.

After a full night of sophisticated metropolitan revelry -- dinner and a show, the grand Manhattan experience -- you hail a yellow cab. The City’s no steel-souled machine; you’re exhausted yet exhilarated. Cheek against the cool window, you look back at the never-sleeping skyline as you fly over the bridge, past brownstones, Bushwick, and Bed-Stuy. Tonight dream of wonders behind and adventures ahead, of engineered magnificence and whom you might meet in far Montauk.

Who deserves a palace? Royal inheritors of old hoards? Fae folk with the power to spin castles from clouds and ice?

At the end of the 1800s, a clique of Ukrainian horse breeders commissioned a sumptuous hoof-shaped club of carved wood, crystal chandeliers, marble fireplaces, silk-upholstered walls, and a majestically curving central staircase crowned with a great glass vault.

Decades later, this opulent casino was converted by the Soviets into a House of Scientists, meeting place for promising minds and home for their respected elderly forebears.

Fairy queens may rule forever, but human wealth lasts only so many generations. By the ruins of Lviv's High Castle you look over the fine city, then head south on cobblestoned streets. You turn at the seated Statue of Liberty flanked by allies to her struggle.

Formally dressed and with invitation in hand, you enter the former casino, tonight the palatial site of an elegant ball. Borys takes your coat as you admire his blue and yellow pocket square. Sergei, Stanislaw, and Valentin beckon you upstairs to join in their plans to visit cosmic wonders.

A spiral is flat, like a watch spring or a nautilus shell. A helix, on the other hand, stretches into the third dimension, like the spring in a clicky ballpoint pen or the contrail of a jet circling into the sky. So a "spiral staircase" is really a helix. The genetic code coiled up in your cells forms a double helix - two strands twisted together.

500 years before Rosalind Franklin's X-ray photographs revealed the structure of DNA, Donato Bramante designed a double helix of ramps. People spiraling up never met those spiraling down. His masterpiece inspired Giuseppe Momo's braided staircase in the Vatican museums.

How much of your essence is determined and how much a product of your own decisions? As you walk the staircase's serpentine figure eights, old scenes repeat in your mind. Some bring warm relaxing pleasure. Other memories twist you into cold knots. It's challenging to focus on your accomplishments while learning from mistakes and moving on.

Like the ornate metal railing, you contain multitudes. No one is all good or all bad. You deserve the peace of a restful night's sleep.

Anything that lasts long enough becomes a museum. Old churches. Decommissioned power plants. Places with space and light and years and years of history inside. Even I have become a curated collection of a lifetime's memories.

My favorite museum was once a rail terminal. A century ago, Gare d'Orsay was the world's first electrified station and the northern end of the Paris-Orleans line. I am still transported there, though today the views are in frames instead of through railcar windows.

Now you wander through levels of wonders: Degas' dancers. Manet's bouquets. Seurat's dots. Cezanne's impressions. Van Gogh's visions.

My favorite is a sculpture: a striding white polar bear. May you, too, dream of riding through the halls, bear claws clicking on the stone floors, past great arched windows and great art, beneath the old station's grand clock, still proudly marking time for travelers.

What stands out as you wander the old streets of York? Half-timbered walls. Footfalls on cobblestones. Rhythmically named snickelways.

You walk up Whip-Ma-Whop-Ma-Gate, left through King’s Square then left again and there you are in a bright and darkened land, once The Great Flesh Shambles, now a patchwork of present and 500 years past. The butchers are long gone, but their hooks still adorn the nearly touching jettied upper floors of the shops lining this narrow lane.

Our dreams often have missions: find the jewel; master flight; defeat the beast. Some quests are more mundane, but no less delightful a visit to the Green World for that. Tonight you have errands to run: collect a sachet of tea and a creamy chocolate bar; deliver a note to the ghost of Guy Fawkes; recite from a chapbook signed by W. H. Auden.

Reaching Little Shambles, the winds of dawn blow softly round your dreaming head. Sleep a little longer, watched by every human love.

Buildings have personalities. Figuratively here; literally in the Green World -- die Grune Welt. Meet wunderbar characters tonight, a lovingly eccentric Familie in a famously scented city on the Rhein.

This warm evening, Oma the Harbor Christmas Market is away for the season. But rich, overindulgent Onkel Schokoladenmuseum more than makes up for any missing joy. Oh-so-modern Cousin Ludwig invites you to admire his Picassos. Elegant Schwester Hohenzollernbrucke gracefully spans the river. Great Tante Gothic Cathedral, her twin spires tallest in the world, is a bit intimidating. You prefer her gentler Romanesque sister, the Great Saint Martin Church - she's a comforting presence, benevolently watching over your gathering with a cluster of colorful friends by the Fischmarkt fountain.

It's more fun to explore a city with someone who knows its ins and outs. In Dream Land, don't just rudely enter a restaurant. Step up, introduce yourself, then bask in his century-spanning tales: "I was a Benedictine Abbey once, some years before I was hurt in the war..."