1

Lake Superior lives up to its name

Image: Jacob Skowronek

Lake Superior is the largest, deepest, and coldest of the five. It holds more water than the other four lakes combined—enough to cover North and South America in a foot of water. At 31,700 square miles, it’s the largest freshwater lake by surface area in the world.

2

Only one is fully American

Image: Ioann-Mark Kuznietsov

Lake Michigan is the only Great Lake entirely within the jurisdiction of the United States. It touches four states—Wisconsin, Illinois, Indiana, and Michigan—and its shores are home to major cities like Chicago and Milwaukee. As if this wasn’t enough, this lake also boasts the world’s largest freshwater sand dunes.

3

They create their own weather

Image: Srikanta H. U

The Great Lakes have a powerful influence on regional weather, especially through the phenomenon of "lake-effect snow." As cold air sweeps over the warmer lakes, it picks up moisture, resulting in heavy snowfall in cities like Buffalo, Cleveland, and Chicago. The lakes also generate localized storms that can rival oceanic tempests in intensity. Yet, not all is harsh; these unique conditions help create microclimates that are perfect for agriculture, supporting a range of crops across the region.

4

A shipwreck graveyard

Image: Vlad Tchompalov

Prone to stormy and unpredictable weather, the Great Lakes are home to over 6,000 shipwrecks. The most infamous of these, the SS Edmund Fitzgerald, sank in Lake Superior during a violent storm in 1975, inspiring Gordon Lightfoot's iconic ballad. In fact, many of these wrecks are remarkably well-preserved, thanks to the cold freshwater, which slows down the decay process and keeps these sunken ships intact for decades.

5

They contain a fifth of the world’s freshwater

Image: Sime Basioli

The Great Lakes hold about 21% of the world's fresh surface water. That’s roughly six quadrillion gallons—enough to submerge the lower 48 states under about 10 feet of water. Given this staggering quantity, it's no surprise that the lakes are crucial to American drinking water, agriculture, and industry.

6

The Erie Canal’s role

Image: Lucy M

Opened in 1825, the Erie Canal linked the Great Lakes to the Atlantic Ocean via the Hudson River, transforming trade and settlement patterns. It played a pivotal role in making New York City an economic powerhouse and significantly accelerated the movement of goods between the Midwest and the East Coast. While most traffic now flows through the larger St. Lawrence Seaway, the Erie Canal remains a key chapter in U.S. history.

7

When the Niagara Falls stood still

Image: Vishwesh Jirgale

In 1969, engineers temporarily halted the flow of Niagara Falls due to concerns that erosion was progressing so rapidly the falls could disappear in a few years. After a thorough inspection by the Army Corps of Engineers, they concluded that no immediate maintenance was necessary. Despite this, the endeavor was far from futile—it provided valuable insights that would guide future preservation efforts for the iconic falls.

8

America’s forgotten "Third Coast"

Image: Richard Main

The Great Lakes coastline spans about 10,900 miles, which makes it longer than the U.S. East and West Coasts combined. This hidden "Third Coast" features sandy beaches, towering cliffs, and picturesque lighthouses, making it a popular destination for tourism and outdoor recreation.

9

Once an ancient ocean

Image: Andrzej Kryszpiniuk

Millions of years ago, the region now holding the Great Lakes was covered by an ancient sea. Over time, glaciers carved out the massive basins, which filled with meltwater after the Ice Age. The evidence of this transformation is still visible in the region’s fossils and rock formations.

10

Chicago River’s historic reversal

Image: Jake Leonard

In 1900, engineers reversed the flow of the Chicago River to prevent sewage from polluting Lake Michigan, the city’s drinking water source. Using a system of canals, the river was redirected toward the Mississippi River watershed, an astonishing feat of engineering that still works to this day.

11

Protected by an international treaty

Image: Hermes Rivera

The 1909 Boundary Waters Treaty between the U.S. and Canada governs the Great Lakes, ensuring cooperative water management. It led to the creation of the International Joint Commission, which helps both nations resolve disputes and protect this vital natural resource.

1

What are bills made of?

Unlike other currencies, dollar bills are not made of paper or plastic. U.S. dollar bills are made from a special fabric blend composed of 75% cotton and 25% linen. This mix makes the bills extremely durable and resistant, and they can be folded about 4000 times before tearing.

2

What bills are valid?

Any U.S. dollar bill that was legally printed is valid, no matter how old, as American currency does not have an expiration date. While some bills might not be accepted by businesses of foreign exchange services due to their condition or if they are a discontinued version of the bill, the bills themselves are still valid, and American banks will accept them, though they might take them out of circulation.

3

American leaders

Five bills have a depiction of an American president. The exceptions are the $10 bill, with Alexander Hamilton on the front, and the $100 bill, with Benjamin Franklin. The $1 bill, depicting George Washington, is extremely symbolic: several elements are repeated 13 times as a nod to the thirteen colonies, and it showcases the Bald Eagle and the Eye of Providence as a sign of God watching over America.

4

A change in size

Did you know that dollar bills used to be so big that they were nicknamed "horse blankets"? Original dollar bills were 7.4 × 3.1 inches. In 1929, the Treasury Department reduced the size of bills to 6.14 × 2.61 inches to reduce production costs and materials. Old bills, though still valid, are worth much more as collector items.

5

Uniformity

Besides their value and design, all dollar bills have the same size (6.14 × 2.61 inches), color, and weight (1 gram) , which sets American currency apart from other countries where bills of different values are differentiated by size, color, or both. Why doesn’t the U.S. implement differences among bills? The cost of adapting vending machines, bank drawers, and ATMs to new bill sizes would cost billions of dollars.

6

Hard to copy

Originally, dollars were not green, but black. As time passed, green ink was favored, as it was cheap and did not fade as much as black. The new color also prevented people from using black-and-white cameras to create counterfeit money. Currently, dollar bills are predominantly green, but newer versions also include extra colors, such as pink, orange, or purple.

7

A $100,000 bill?

Have you ever seen a $500 or 1,000 dollar bill? What about a $100,000? Up until 1945, the U.S. Treasury printed $500, $1,000, $5,000, $10,000, and $100,000 notes , in addition to the values currently in use. These higher-value notes were mainly intended for bank and government use, but were sought by criminals as they made it easier to hide large amounts of money. Even though they were officially discontinued in 1969, these notes are still valid, though rare, and they have a high worth as collector's items.

8

No numbers

Unlike bills, American coins have different sizes and colors related to their value. Originally, gold, silver, and copper were used for coins, but modern coins are made of copper, zinc, or nickel. Besides their size and design, the value of each coin is printed in letters, not in numbers , alongside depictions of American presidents.

9

Liberty for all (the coins)

By law, all American coins must include six specific details : the word ‘Liberty’, the name of our country, the national motto "In God We Trust", the oldest American motto "E Pluribus Unum", the value of the coin, and the year. Each coin also includes a mint mark that shows where it was made: "P" for Philadelphia, "D" for Denver, "S" for San Francisco, and "W" for West Point.

10

A global currency

The American dollar is one of the most powerful currencies in the world, acting as a backbone for international trade and finances. It is estimated that two-thirds of the physical dollars in circulation are outside American territory. Besides the U.S. and its territories, eight sovereign nations have the U.S. dollar as their official currency, with several more accepting it as legal tender.

1

There's an unexplained billion-year gap

Look closely at the canyon walls, and you'll notice something strange: a clean, sharp line where ancient rock simply stops, and a much younger layer begins directly above it.

This geological puzzle is called the "Great Unconformity," and it represents over a billion years of rock layers that are simply absent , as though that stretch of time never happened. In some spots, rock dated 1.8 billion years old sits directly beneath rock that is only 520 million years old. Where did the missing billion years go?

The leading theory involves the violent breakup of an ancient supercontinent, but scientists are still piecing it together.

2

During the Cold War, it hid a nuclear fallout shelter

During the Cuban Missile Crisis in 1962, the U.S. government converted part of the Grand Canyon Caverns into a fallout shelter. This dry cave system, more than 200 feet underground, was stocked with enough food and water to sustain 2,000 people. Naturally, it was never occupied, and the supplies were never used.

The caverns have since been transformed into a tourist attraction, with organized tours winding through the same underground chambers that were once intended as a refuge from nuclear war. You can even book a night's stay there.

3

The Federal Aviation Administration was founded after a crash over the canyon

In 1956, two commercial passenger planes collided in midair over the eastern Grand Canyon, killing all 128 people on board both crafts. Rescue teams struggled to reach the wreckage deep inside the canyon, and the extreme heat of the crash had caused the planes' aluminum to fuse with the bedrock. There were no survivors.

The disaster exposed a terrifying truth: the U.S. air traffic control system was dangerously outdated, relying on pilots' visual estimates and rough guesswork from controllers , with no way to separate fast-moving aircraft from slow ones, or instrument-flying planes from those navigating by sight. Congress responded by passing legislation that created both the Federal Aviation Administration (FAA) and the National Transportation Safety Board.

4

A hoax suggested that an Egyptian civilization had lived there

In 1909, the Arizona Gazette reported that an explorer named G. E. Kinkaid had discovered a vast underground citadel inside the canyon, filled with artifacts linked to ancient Egyptian civilization. He even claimed the expedition had been funded by the Smithsonian.

This story described hieroglyphics on the walls, mummies in the chambers, and relics pointing to a direct connection with the Egypt of the pharaohs. It was incredibly detailed, and it was, of course, a hoax. No evidence for any of Kinkaid's claims ever surfaced.

5

Fewer than 100 people have ever hiked its full length

Among the few people who have completed the through-hike of the Grand Canyon is Jen Hogan, the first woman to accomplish it, finishing her journey in 2021–2022.

It’s a full 800-mile length below the rim. The route involves extreme heat, flash floods, near-impassable areas, and stretches with no water or trail whatsoever. Around 60 or 70 people have reportedly accomplished it. This makes it one of the most exclusive feats on Earth.

6

The Grand Canyon's rocks predate dinosaurs entirely

Visitors scanning the canyon walls for fossils are often surprised to learn they won't find any dinosaur bones here. The rock layers of the Grand Canyon are simply older than dinosaurs. This fact alone can be shocking: staring at its walls means staring at marine fossils from as far back as 1.2 billion years ago. Some of its caves hold the remains of ancient mammals. The canyon is a window into a world that existed long before the dinosaurs, when the land that is now Arizona lay beneath a shallow sea.

7

The park is bigger than Rhode Island

Numbers alone rarely capture the Grand Canyon's scale, so here's a different approach. Rhode Island covers about 1,214 square miles, and the Grand Canyon National Park spans 1,904 square miles.

The canyon's depth exceeds four Empire State Buildings (which is 1,454 feet) stacked on top of one another. That’s 6,093 feet at its deepest point.

8

But it's not the deepest canyon on Earth

For all its grandeur, the Grand Canyon does not hold the depth record. Pictured above, the Yarlung Tsangpo Grand Canyon in Tibet, China, plunges to 17,567 feet, which is nearly three times deeper. Carved by the Yarlung Tsangpo River as it cuts through the eastern Himalayas, that canyon is so remote and extreme that it remained largely uncharted until the late 20th century.

9

It is home to a pink rattlesnake found nowhere else on Earth

The Grand Canyon Pink Rattlesnake has a pinkish-red coloring that matches the canyon's own distinctive rock walls so closely that it's nearly invisible. It is found nowhere else in the world. Officially classified as Crotalus oreganus abyssus , it has darker diamond-shaped markings along its back that deepen the camouflage further.

10

There's a village at the bottom: Supai Village

For over 1,000 years, the remote village of Supai has been home to the Havasupai Tribe, the People of the Blue-Green Waters. It is located an eight-mile hike from the rim, but sits roughly 3,000 feet deep inside the Grand Canyon.

The U.S. Department of Agriculture has called it the most remote community in the contiguous United States, and it has no automobiles and no road access. The only ways in are on foot, by mule, or by helicopter. It is also the only place in the United States where the postal service still delivers mail by mule train.