15 Mind-Blowing Facts About the World's Most Famous Landmarks

1. The Eiffel Tower Grows Taller in Summer

Paris's iconic Eiffel Tower, designed by Gustave Eiffel and completed in 1889, stands as a marvel of 19th-century engineering. What most visitors don't realize is that the tower actually changes height depending on the temperature. Due to thermal expansion, the 10,100 tons of wrought iron that make up the tower expand in hot weather and contract in cold. This can cause the 1,063-foot (324-meter) structure to grow by as much as 6.75 inches (17 centimeters) during the hottest summer days. To accommodate this natural expansion and contraction, the tower's four legs rest on flexible joints rather than being rigidly fixed to its foundations. Originally built as a temporary structure intended to stand for only 20 years, the tower has now become France's most recognizable symbol and welcomes nearly 7 million visitors annually. Another less-known fact: The Eiffel Tower has to be completely repainted every seven years, requiring 60 tons of paint and a team of 25 painters working for 18 months.

[Image suggestion: Side-by-side comparison showing the Eiffel Tower's height difference between winter and summer, with an infographic explaining thermal expansion]

2. The Great Wall of China Is Not Visible from the Moon

Despite the popular myth that the Great Wall of China is the only human-made structure visible from space or even the moon, this claim is entirely false. From the Moon, no human-made objects are visible at all—even continents are barely distinguishable. From low Earth orbit (where the International Space Station orbits), the Great Wall is actually very difficult to spot with the naked eye due to its relatively narrow width and the fact that it's built from materials similar in color to the surrounding landscape. Other human constructions like highways, airports, dam reservoirs, and city lights are actually much easier to see from space. What is remarkable about the Great Wall, however, is its sheer length—stretching approximately 13,171 miles (21,196 kilometers) through mountains, deserts, and grasslands. Built over multiple dynasties spanning more than 2,000 years, some sections of the wall are now in ruins or have disappeared entirely, while others have been extensively restored for tourism. Contrary to another common myth, the mortar used in some parts of the wall was not strengthened with human bones or rice—it was actually made from a mixture of lime and sticky rice, which proved remarkably strong and durable.

[Image suggestion: Actual photograph of Earth from the Moon showing the invisibility of the Great Wall, alongside a close-up aerial view of the Wall]

3. The Statue of Liberty Was Originally Copper-Colored

Lady Liberty hasn't always worn her iconic green patina. When the Statue of Liberty was first assembled and unveiled in New York Harbor in 1886, she was actually a shiny copper color, similar to a new penny. The statue's distinctive green appearance developed gradually over about 30 years as the copper skin, just 3/32 of an inch thick (about the thickness of two pennies), oxidized from exposure to air and seawater. This natural process created a patina of copper carbonate that now protects the underlying metal from further corrosion. The statue was a gift from the people of France to celebrate the centennial of American independence and commemorate the friendship between the two nations during the American Revolution. Designed by French sculptor Frédéric Auguste Bartholdi with an internal framework by Gustave Eiffel (of Eiffel Tower fame), the statue consists of 350 individual pieces shipped from France in 214 crates. Her face was reportedly modeled after the sculptor's mother, Charlotte Bartholdi. Originally, the torch was intended to function as a lighthouse, but its light proved too dim for practical navigational use, though it was later retrofitted with electric lights.

[Image suggestion: Side-by-side images showing the original copper color (digitally recreated) next to the current green statue, with a timeline showing the gradual color change]

4. The Pyramids of Giza Were Once Covered in Smooth White Limestone

The ancient Pyramids of Giza that we see today, with their stepped, weathered stone blocks, would be unrecognizable to the pharaohs who commissioned them. When originally built around 4,500 years ago, these massive monuments were encased in smooth white limestone with a polished surface that would have gleamed brilliantly in the Egyptian sun. Some of these casing stones were as heavy as 15 tons each and were fitted so precisely that a knife blade could not be inserted between them. This reflective surface would have made the pyramids visible from the mountains of Israel and possibly even from the moon. The casing stones remained largely intact until a major earthquake in 1301 CE loosened many of them. Subsequently, most were removed to build mosques, fortresses, and other structures in nearby Cairo, leaving only a few at the base of the Great Pyramid. Additionally, each pyramid originally had a gold-plated capstone (called a pyramidion) at its apex. Archaeological evidence also suggests the ancient Egyptians maintained an extensive canal system that allowed materials to be transported by boat right to the pyramid construction sites, despite their location on a plateau above the Nile River's floodplain.

[Image suggestion: Artist's rendering of the original appearance of the Pyramids with their limestone casing and gold capstones, compared with their current appearance]

5. The Taj Mahal Has Perfect Symmetry, Except for One Room

The Taj Mahal, completed in 1643, is renowned for its perfect symmetry—a deliberate design feature that reflects the Islamic emphasis on harmony and balance. However, there is one intentional asymmetrical element in the entire complex: the tomb of Emperor Shah Jahan himself. When Shah Jahan commissioned the ivory-white marble mausoleum for his favorite wife, Mumtaz Mahal, who died during childbirth, he had planned to build an identical black marble structure across the river for his own tomb. Financial constraints and his imprisonment by his son Aurangzeb prevented this plan, and he was instead buried alongside his wife in the Taj Mahal. Since his casket was placed next to hers, it disrupts the otherwise perfect symmetry of the chamber. The Taj incorporates numerous optical illusions, including minarets that lean slightly outward—a design feature ensuring they would fall away from the main dome in case of collapse during an earthquake. The complex also features an ingenious acoustic design where whispers can be heard throughout the main chamber due to the dome's perfect curved surface. The entire structure is also designed to respond to changing light conditions, appearing to glow and subtly change color throughout the day.

[Image suggestion: Overhead diagram of the Taj Mahal highlighting the perfect symmetry alongside a photo of the asymmetrical tomb chamber]

6. The Leaning Tower of Pisa Was Designed to Lean (Just Not This Much)

Contrary to popular belief, the Leaning Tower of Pisa was intentionally designed with a slight lean—though not nearly as dramatic as its current 4-degree tilt. The tower's architect, Bonanno Pisano, planned a small lean to make the structure visually unique among the other buildings in Pisa's Cathedral Square. However, construction began in 1173 on unsuitable soil—a mere three-meter foundation set in weak, unstable subsoil. By the time the third floor was completed in 1178, the tower had begun to sink noticeably on its south side. Construction was halted for nearly a century due to Pisa's wars with neighboring cities, and this inadvertently allowed the soil to settle and stabilize, preventing the tower from collapsing entirely. When building resumed in 1272, engineers tried to compensate for the tilt by building upper floors with one side taller than the other, giving the tower its distinctive curved appearance. Over the centuries, the tower continued to lean at a rate of about 1-2 millimeters per year, reaching a tilt of 5.5 degrees by 1990. Engineering work between 1993 and 2001 reduced the lean to a safer 4 degrees, which experts believe will keep the tower stable for at least 200 more years.

[Image suggestion: Diagram showing the tower's original intended design alongside its actual curved structure, with annotations explaining the correction attempts]

7. Stonehenge's Stones Were Transported Over 140 Miles

The mysterious prehistoric monument of Stonehenge becomes even more impressive when you consider the extraordinary effort involved in its construction. The largest stones, known as sarsens, weigh up to 30 tons each and were transported about 20 miles from Marlborough Downs. Even more remarkably, the smaller bluestones (which still weigh 2-5 tons each) originated from the Preseli Hills in Wales—about 140 miles away from the Salisbury Plain where Stonehenge stands. This incredible feat was accomplished without wheels, roads, or draft animals around 5,000 years ago. Recent archaeological evidence suggests the bluestones may have been moved using a combination of wooden sledges, rollers, ropes, and possibly water transport along the coast and rivers. The precision of Stonehenge's construction is equally impressive—the lintels (horizontal stones) atop the massive upright sarsens were carefully shaped with interlocking joints similar to modern carpentry techniques, featuring tongue-and-groove connections and mortise-and-tenon joints. The monument is also astronomically aligned; its main axis is carefully positioned with the sunrise on the summer solstice and sunset on the winter solstice, suggesting it may have functioned as a prehistoric observatory or celestial calendar.

[Image suggestion: Map showing the transportation routes of the different stones from their quarry sites to Stonehenge, with an inset showing the sophisticated joinery techniques]

8. Mount Rushmore Has a Secret Chamber Behind the Presidents' Heads

Hidden behind Abraham Lincoln's head at Mount Rushmore lies a secret chamber that most of the monument's three million annual visitors never learn about. Conceived by sculptor Gutzon Borglum as the "Hall of Records," this 70-foot tunnel was intended to contain the nation's most important historical documents and artifacts, preserving them for future civilizations. Borglum envisioned an 800-foot stairway leading to a grand hall with bronze and glass cabinets displaying the Declaration of Independence, the Constitution, and other historical treasures. The chamber was also designed to explain why Washington, Jefferson, Roosevelt, and Lincoln were chosen to be immortalized in the granite mountainside. Borglum died in 1941 before this ambitious vision could be realized, and World War II halted further work on the project. The rough-hewn chamber remained empty and unfinished until 1998, when a repository of sixteen porcelain enamel panels was finally installed. These panels contain the text of the Declaration of Independence, the Constitution, the Bill of Rights, and a short history of the United States. Sealed in a teakwood box and placed in a titanium vault, these panels are intended for future generations, perhaps thousands of years from now, to understand the monument's significance.

[Image suggestion: Photograph of the seldom-seen Hall of Records entrance behind Lincoln's head, alongside Borglum's original concept drawing of the planned grand chamber]

9. The Sydney Opera House Was Supposed to Take 4 Years to Build, But Took 14

The Sydney Opera House, one of the most distinctive buildings of the 20th century, was originally estimated to cost $7 million and take four years to build. Instead, it took 14 years and cost $102 million—more than 14 times the original budget. The dramatic cost overrun was largely due to the unprecedented complexity of Danish architect Jørn Utzon's design. When Utzon won the international design competition in 1957, his submission consisted of simple sketches rather than detailed plans. Engineers initially declared the iconic "shells" of his design unbuildable, and it took years to develop a workable approach—eventually solved by deriving all the shells from sections of a single sphere, which simplified the geometry and construction. Political pressure, cost overruns, and disagreements with the new government led to Utzon's resignation in 1966, and he never returned to Australia to see his masterpiece completed. The interior was finished by a team of Australian architects who made significant changes to Utzon's original vision. When the Opera House was finally opened by Queen Elizabeth II in 1973, Utzon's name wasn't mentioned during the ceremony. It wasn't until 1999 that the Sydney Opera House Trust reconciled with Utzon, appointing him as a design consultant for future changes to the building. In 2007, the Opera House became a UNESCO World Heritage Site—making it one of the youngest cultural sites ever to receive this designation.

[Image suggestion: Utzon's original competition sketches alongside early construction photos showing the engineering challenges of the shell structures]

10. The Forbidden City Has 9,999 Rooms (Not 10,000)

Beijing's Forbidden City, the imperial palace complex of China from 1420 to 1912, is often said to contain 9,999 rooms—one room short of the perfect number 10,000. This was supposedly because only the gods could possess 10,000 rooms. While this makes for a compelling story highlighting the symbolic importance of numbers in Chinese culture, the reality is slightly different. The "9,999 rooms" refers not to actual rooms but to "bays" (间, jiān)—a traditional Chinese architectural counting unit representing the space between four columns. By this traditional counting method, the Forbidden City indeed has 9,999.5 bays (the half represents a special structure that doesn't quite constitute a full bay). In terms of actual rooms as we understand them today, the complex contains about 8,700 distinct spaces. The number 9 was associated with the emperor, as it was considered the largest single-digit number and symbolized the supreme authority of the Son of Heaven. This significance is evident throughout the Forbidden City—door studs were arranged in rows of nine, and important ceremonies often began at the ninth hour. The complex was designed to withstand earthquakes using innovative interlocking wooden brackets that allow the buildings to flex without collapsing, a system that has preserved many structures through numerous seismic events over six centuries.

[Image suggestion: Aerial view of the Forbidden City highlighting its symmetrical layout, with an inset diagram explaining the traditional "bay" counting system]

11. The Colosseum's Original Name Wasn't the Colosseum

Ancient Romans never called their iconic amphitheater "the Colosseum." When Emperor Vespasian began construction around 70-72 CE, the structure was officially named the Flavian Amphitheater (Amphitheatrum Flavium) after his family dynasty. The name "Colosseum" emerged much later, likely in the Middle Ages, derived from the colossal 100-foot bronze statue of Emperor Nero—the Colossus Neronis—that stood nearby. This statue had been modeled after the Colossus of Rhodes and originally depicted Nero, but subsequent emperors modified it to represent the sun god. Another little-known fact about the Colosseum involves its inaugural games in 80 CE, which lasted an astonishing 100 days and featured the slaughter of approximately 9,000 animals. The arena floor that we associate with gladiatorial combat was actually a wooden platform covered with sand (the Latin word for sand, "harena," is the origin of our word "arena"). Beneath this floor lay the hypogeum—an elaborate two-level subterranean network of tunnels, cages, and mechanical lifting systems that allowed for dramatic entrances as animals and fighters were raised to the arena floor through trapdoors. The Colosseum could also be rapidly flooded for mock naval battles (naumachiae) during its early years, before the hypogeum was constructed. Despite losing nearly two-thirds of its original structure to earthquakes, stone robbers, and time, the Colosseum remains an engineering marvel that could seat 50,000-80,000 spectators and evacuate them in just minutes through its 80 entrance/exit arches.

[Image suggestion: Artist's reconstruction of the original Colossus statue next to the Flavian Amphitheater, with a cutaway diagram revealing the hypogeum beneath the arena floor]

12. There Are 1,710 Steps to the Top of the Eiffel Tower

While most of the Eiffel Tower's seven million annual visitors use the elevators, the more adventurous can climb the 1,710 steps to the top observation deck. However, this stair trek is not always available—typically, tourists can only climb to the first and second floors (328 and 674 steps respectively), as the stairs to the top level are usually reserved for emergency use. When Gustave Eiffel designed his tower in the 1880s, he included a small private apartment for himself near the top, where he entertained illustrious guests like Thomas Edison. This exclusive space, unavailable to the public during Eiffel's lifetime, has now been restored and can be viewed through a window. The tower's intricate ironwork isn't just for show—its design, with open lattice work, allows wind to pass through rather than creating pressure against a solid surface. This innovative approach means that despite its height and seemingly delicate appearance, the tower sways only 6-7 centimeters (about 3 inches) in strong winds. The Eiffel Tower was also designed to be easily dismantled—the entire structure is held together by 2.5 million thermally assembled rivets, and no drilling or shaping was required on site. Each of the 18,000 metallic parts was designed with precision down to one-tenth of a millimeter, a remarkable achievement for 19th-century engineering.

[Image suggestion: Spiral staircase within the Eiffel Tower with a counter showing the step numbers at different levels, alongside a photo of Eiffel's restored private apartment]

13. Easter Island Heads Actually Have Bodies

The iconic stone statues of Easter Island, known as moai, are much more than just heads—they have bodies buried beneath the surface. While the massive stone faces staring inland from the edges of Easter Island (Rapa Nui) have become embedded in popular culture as "Easter Island heads," archaeological excavations have revealed that these monolithic figures extend well below ground level. Some of the buried portions are adorned with previously unknown petroglyphs and designs. The largest standing moai is 33 feet tall and weighs approximately 82 tons, while an unfinished statue in the quarry would have stood 69 feet tall and weighed about 270 tons. Contrary to another common misconception, the moai were not carved by an extinct or alien civilization—they were created by the indigenous Rapa Nui people between approximately 1250 and 1500 CE. The islanders also managed to transport these massive carvings miles from the quarry to their coastal platforms without the benefit of wheels, cranes, or large animals. Recent experimental archaeology has demonstrated that the statues could have been transported in an upright position using only rope and teams of people who rocked the moai from side to side in a "walking" motion. This ingenious solution aligns with local legends that the statues "walked" to their final locations. The statues originally had eyes made of coral with obsidian or red scoria pupils, which would have appeared startlingly lifelike when complete.

[Image suggestion: Excavation photos showing the buried bodies of moai alongside a traditional "head only" view, with an illustration of the theorized transportation method]

14. The Golden Gate Bridge Was Supposed to Be Black and Yellow

The distinctive "International Orange" color of San Francisco's Golden Gate Bridge—arguably its most recognizable feature—was never intended to be permanent. When the bridge was being designed in the 1930s, the U.S. Navy pushed for a black and yellow striped pattern to ensure maximum visibility for passing ships in the foggy bay. Other suggestions included carbon gray, aluminum, or dark gray to blend with the natural environment. The bridge's consulting architect, Irving Morrow, noticed that the primer being used on the steel—a reddish-orange rust-preventative coating—contrasted beautifully with the natural surroundings, the blue bay, and San Francisco's typically gray fog. He successfully advocated for a similar permanent color, creating the iconic hue we now associate with the bridge. The paint job isn't just for aesthetics—it provides crucial protection from the salt air that would otherwise quickly corrode the steel structure. Maintenance crews continuously touch up the paint year-round, completely repainting sections on a rolling basis rather than repainting the entire bridge at once. Approximately 5,000-10,000 gallons of paint are used each year for touch-ups. The bridge's distinctive color is now trademarked and has its own precise color formula: C=0, M=69, Y=100, K=6. When opened in 1937, the Golden Gate Bridge was the longest suspension bridge in the world, with a main span of 4,200 feet—a record it held until New York's Verrazano-Narrows Bridge opened in 1964.

[Image suggestion: Mock-up showing what the bridge would have looked like with the Navy's proposed black and yellow stripes, alongside a photo of the actual International Orange bridge]

15. The Washington Monument Has a Visible Color Change Halfway Up

Observant visitors to Washington D.C. might notice that the Washington Monument has a subtle but distinct color change about one-third of the way up its 555-foot height. This two-tone appearance is a visible reminder of the monument's troubled construction history. Work began in 1848, but in 1854, the Washington National Monument Society ran out of funds and construction halted with the obelisk only 150 feet tall. The unfinished stump sat untouched for 25 years, throughout the Civil War and its aftermath. When construction finally resumed in 1876 under government funding, the original quarry could no longer be used, so stone was sourced from a different quarry. Although both sections are made of white marble, the different quarries and 25 years of weathering on the bottom section created the slight but noticeable color variation that persists today. Inside the monument are 193 memorial stones donated by individuals, societies, cities, states, and nations, many of which are visible to visitors taking the elevator or stairs. One of the more unusual stones came from the ancient Temple of Concord in Rome, sent by Pope Pius IX. However, this stone never made it into the monument—in 1854, members of the anti-Catholic "Know-Nothing" political party stole the stone during their brief takeover of the Monument Society and allegedly threw it into the Potomac River. The Washington Monument remains the world's tallest stone structure and, at the time of its completion in 1884, was the tallest man-made structure on Earth.

[Image suggestion: Close-up photograph highlighting the color change on the Washington Monument with a historical timeline showing the gap in construction]