1

Seattle Underground City

Did you know the remnants of Seattle's original streets are still accessible? Beneath the bustling streets of modern-day Seattle lies the Underground City , a network of subterranean passageways that formed the ground level in the 1800s.

By the end of the 19th century, after the Great Seattle Fire, it was decided to rebuild the city at a higher elevation to combat frequent flooding . So, these original streets, sidewalks, and storefronts were buried, and with it, much of their history.

Guided tours take people through tunnels and ladders and retell real and eerie stories about the history of the Underground City.

2

Luray Caverns

Image: Robert Thiemann

Have you ever heard of the underground Stalacpipe Organ ? Not only is it a one-of-a-kind interaction between keyboards and cavern stalactites, but it is also the largest musical instrument in the world, according to Guinness World Records.

This instrument lives in the Luray Caverns, Virginia. It consists of an electric console that taps on these ancient stalactites of varying sizes to produce musical tones. A subterranean wonder, these caverns are also known for their extraordinary size , housing towering stalactites and stalagmites, mirrored pools, and delicate drapery-like calcite formations.

3

The Underground Gardens of Baldassare Forestiere

Image: Adrian Botica

This stunning subterranean retreat was built entirely by hand. Tucked under the sun-scorched landscape of Fresno, California, lie the Underground Gardens of Baldassare Forestiere . They are the life’s work of Baldassare Forestiere, a Sicilian immigrant who started digging in the early 1900s to escape the Central Valley's oppressive heat.

Over 40 years, drawing inspiration from ancient Roman catacombs , Forestiere carved an elaborate network of underground rooms, passageways, grottoes, and courtyards that span 10 acres.

A unique masterpiece, the gardens are open with guided tours that lead guests through beautifully designed spaces featuring skylights, arches, and alcoves. This oasis also boasts an array of fruit trees, including citrus, figs, and olives.

4

Ruby Falls

Image: Goodfreephotos_com

Colorful and breathtaking, the Ruby Falls is a geological wonder located inside Lookout Mountain near Chattanooga, Tennessee.

Hidden over 1,000 feet below the mountain's surface, this waterfall cascades 145 feet into a pool , making it one of the tallest underground waterfalls open to the public.

Visitors enter the mountain and descend via elevator. Then, they walk through stunning cave formations such as stalactites, stalagmites, and flowstone. At the waterfall chamber, multicolored lights –powered by renewable energy– illuminate the falls. Lantern-lit tours are also offered as a chance to visit the marvel with a different charm.

5

The Catacombs of Green-Wood Cemetery

Image: Joy Ernst

Arched tunnels of tranquil, sacred vaults lie beneath the Green-Wood Cemetery in Brooklyn, New York. Built in the mid-19th century, these catacombs were designed as a prestigious resting place for the city’s elite , prominent families.

While the catacombs are typically closed to the public, special events are sometimes organized to welcome visitors, such as art expositions, guided history tours, and candlelit tours seasoned with live music and storytelling.

Outside, where the sun does reach, await the serene landscapes and remarkable monuments of the cemetery, which is itself a National Historic Landmark .

6

The Lost Sea

Image: Roberto Nickson

The largest underground lake in America is in Tennessee. Hidden within the Craighead Caverns in Sweetwater, this enormous body of water lies in a cave system filled with fascinating formations, such as stalactites, stalagmites, and rare anthodites, also known as "cave flowers."

A National Natural Landmark, this lake marvels scientists, who are yet unaware of the exact extension of its waters. Those who visit can embark on a boat ride called "The Lost Sea Adventure," first walking inside the cavern before reaching a boat to navigate these ethereal sights.

7

Mammoth Cave National Park

Image: Sherin Jacob

The Mammoth Cave National Park is home to the longest cave system in the world . Located in central Kentucky, it extends over 420 miles of explored passages and many more likely undiscovered. Enormous chambers, underground rivers, a labyrinth of tunnels, and gypsum crystal formations can all be found at this site.

The park has been declared a UNESCO World Heritage Site and an International Biosphere Reserve. It also includes over 52,000 acres of protected land on the surface, renowned for its lush forests and diverse wildlife.

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Carlsbad Caverns National Park

Image: Cason Asher

A large bat colony lives in the Carlsbad Caverns National Park in New Mexico, but that’s not its only charm. The park boasts over 100 caves, with its centerpiece being the immense Carlsbad Cavern.

The cavern includes the Big Room, one of the largest underground chambers in North America, spanning 8.2 acres. Visitors can descend via an emblematic natural entrance or by elevator, dropping 750 feet underground. Stalactite formations like the Giant Dome, the Hall of the White Giant, and the Chandelier are some of the caves' breathtaking highlights.

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Indian Echo Caverns

Image: Magda Ehlers

The Indian Echo Caverns, which have been open to the public since the early 1920s, are carved into the limestone of the Appalachian Mountains. Located near Hummelstown, Pennsylvania, this site gets its name from the echoes heard within the cavern’s chambers , which were once believed to be mystical by Native American people in the area.

Unique, immersive sections of the caverns have names like the "Crystal Palace," the "Echo Room," and the "Wedding Room," where, yes, real weddings are sometimes held!

10

Wind Cave National Park

Image: Francesco Ungaro

Wind Cave National Park, located in the Black Hills of South Dakota, is one of the world’s largest caves, but that’s not what it’s most famous for. One signature sight here is the boxwork formation , a rare lattice-like pattern formed by calcite deposits.

The cave system stretches for over 140 miles, though much of it remains unexplored. Popular tours take guests through captivating features like the "Ribbon Room" and the "Crystal Palace."

Why is Wind Cave called that? Mainly due to the "wind" phenomenon that occurs at its entrance. The cave's air pressure causes the entrance to draw in or expel air, depending on atmospheric conditions.

1

Bigfoot

Image: Mandy Bourke

We’ll start with a classic. For many Americans, Bigfoot is the quintessential mystery —a fantastical creature that has fascinated generations. Also known as Sasquatch, Bigfoot is described as a large, hairy, ape-like being that supposedly roams the forests of North America, evading hikers and adventurers. Some believe most sightings result from misidentifying large mammals like black bears, but true believers continue their relentless search for this mythical creature.

2

Area 51

Image: Oliver Pacas

Who would have thought that a number could become synonymous with aliens and mystery? There’s no doubt that Area 51 exists—it is a real and highly classified United States Air Force facility in Nevada. However, most of us know it for the intrigue surrounding it. According to some sources, Area 51 houses crashed spaceships and alien life forms . Of course, the government denies these claims, but to quote the classic TV show The X-Files , some theorists "choose to believe."

3

Amelia Earhart

Image: Tomas Martinez

Amelia Earhart's life was one filled with adventure. She became the first female pilot to fly solo nonstop across the Atlantic Ocean, among many other feats. Beyond her achievements, her magnetic personality and best-selling books made her an international icon, forever cemented as an American cultural icon. Her mysterious disappearance only deepens the intrigue surrounding her: While attempting to become the first female pilot to circumnavigate the globe, Earhart’s plane vanished over the Pacific Ocean —no wreckage or remains were ever found.

4

Mothman

Image: Sonika Agarwal

Moths are sadly often given a bad reputation. Though they are close cousins to the beloved, colorful butterflies, some people find them slightly unnerving. For the people of West Virginia , there’s an even greater reason to find moths scary: The "Mountain State" is home to one of America’s most famous cryptids— the Mothman . According to legend, this eerie creature resembles a man , stands about seven feet tall , and has large white wings and glowing red eyes .

5

Jersey Devil

Image: Tech Nick

If you ever visit South Jersey’s Pine Barrens, be on the lookout for an oddly shaped creature often described as a cross between a kangaroo and a winged beast . If luck (or misfortune) is on your side, you might encounter the fabled Jersey Devil . Many legends surround this creature, but the most popular tells of the cursed thirteenth child of a Pine Barrens resident, forever cursed to haunt this region.

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UFO Sightings

Image: Michael Herren

UFO sightings are the bread and butter of paranormal enthusiasts. Thousands of Americans have reported seeing flashing lights in the sky , unable to explain their origin. In that regard, we’ll focus on what is perhaps the most famous UFO sighting in this article: In 1947 , residents of the town of Roswell, New Mexico , claimed to have seen a UFO crash into the desert.

7

Haunted houses

Image: Ján Jakub Naništa

As soon as October comes around, hundreds of excited families transform their garages into spooky, fun haunted houses. It’s a thrilling activity that brings neighborhoods together, but let’s face it—these aren’t the haunted houses we’re talking about. From the LaLaurie Mansion in New Orleans to the Winchester Mystery House in San Jose , America is home to some of the world’s most terrifying haunted houses—locations definitely not suitable for the faint of heart.

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Chupacabra

Image: Nandhu Kumar

For such a terrifying creature, the English translation of " Chupacabra "—literally " goat-sucker "—somewhat diminishes its mystique. However, don’t let the name fool you. According to legend, this cryptid is a foul beast that preys on livestock , draining their blood. Descriptions of its appearance vary: In Puerto Rico , it is depicted as an alien-like creature , while in the Southwestern United States , it is described as more dog- or wolf-like .

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Marfa lights

Image: Jr Korpa

Many cultures around the world have legends about mysterious lights appearing before wary travelers at night. In our case, the city of Marfa, Texas , is home to a strange phenomenon known as the Marfa Ghost Lights . While scientists suggest a rational explanation—claiming they result from automobile headlights distorted by warm desert air—some still believe the lights have a paranormal origin.

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Chimayó, New Mexico – Land of Healing

Image: Lina Trochez

We’ve covered some dark and gruesome mysteries in this article, so why not end on a lighter note? In New Mexico’s Rio Arriba and Santa Fe counties, Chimayó is home to a remarkable site . Some believers claim that El Santuario de Chimayó , a Roman Catholic church, possesses mysterious healing powers —particularly the "holy dirt" found in a small well at the back of the church.

1

Books

Many of us stash books in closets or basements to save space , but these areas often trap moisture. Over time, humidity can warp covers, yellow pages, and encourage mold growth, especially in older homes.

A better option is open shelving in a living area where air can circulate freely. Keeping books visible not only helps protect them but also encourages reading and makes it easier to enjoy them regularly.

2

Medicine

Bathrooms are the most common place Americans store medication, yet heat and steam can reduce a drug’s effectiveness over time . Moisture can also cause pills to break down faster or labels to peel off.

A cool, dry place like a bedroom drawer or hallway cabinet is generally safer. Keeping medication out of the bathroom helps preserve its potency and makes expiration dates easier to track.

3

Important documents

Birth certificates, insurance policies, and property deeds are frequently scattered across drawers or stacked in filing piles . This makes them hard to find during emergencies and leaves them vulnerable to damage.

Experts suggest using a dedicated fire-resistant file or document box kept in a consistent location. Centralizing paperwork saves time and reduces stress when documents are suddenly needed.

4

Photo albums and loose photographs

Many families store photos in garages or basements, where temperature swings and moisture can cause fading and curling . Once damaged, photographs are often difficult or impossible to restore.

Photos last longest when stored in acid-free boxes kept in interior closets. Proper storage preserves memories and ensures future generations can enjoy family history without deteriorating.

5

Olive oil

Many Americans keep olive oil next to the stove for convenience. Unfortunately, exposure to heat, light, and air causes oil to turn rancid faster , affecting flavor and nutritional value.

A cool, dark cabinet away from appliances is ideal. Storing olive oil in a tightly sealed, opaque container further slows degradation. Proper storage helps olive oil retain its taste longer and prevents waste caused by premature spoilage.

6

Coffee

Coffee is often kept in its original bag on the counter or in the pantry. Exposure to air, light, heat, and moisture gradually degrades its aromatic compounds, dulling its flavor , even if the beans are freshly roasted.

An airtight container stored in a cool, dark place is generally best for preserving aroma and taste. This simple change keeps coffee fresher and makes each cup more enjoyable.

7

Bread

Many people refrigerate bread to keep it fresh, but cold temperatures actually dry it out faster . The result is a dry, stale texture and often unnecessary food waste.

Freezing bread preserves freshness far more effectively. When wrapped tightly to prevent freezer burn, sliced loaves can be toasted straight from the freezer, extending shelf life without sacrificing quality.

8

Spices

Spice racks near the stove are common, but heat and steam weaken flavors over time . Spices may still look fine while losing much of their potency and taste.

A drawer or cool cabinet away from heat helps spices last longer. Keeping containers tightly sealed further protects against moisture and oxidation. Better storage keeps meals flavorful and reduces how often spices need replacing.

9

Toothbrushes

Left uncovered near sinks or toilets, toothbrushes are exposed to moisture and airborne bacteria . This can lead to hygiene issues and faster wear.

Storing brushes upright in a well-ventilated holder that allows them to air-dry completely is generally recommended. Cleaner storage improves longevity and supports better personal hygiene.

10

Batteries

Loose batteries tossed into junk drawers can rub against metal objects such as coins or paper clips, potentially causing short circuits, leaks, or loss of charge . Damaged batteries may ruin devices later.

Keeping batteries stored by type in a labeled container prevents contact issues. Organized storage extends battery life and makes replacements easy to find.