Everyone makes mistakes. You misspell a word on an important assignment, you forget to put the gas cap back on before driving home from the Shell station, and Frank Langella agrees to play Skeletor in the Masters of the Universe movie. However, sometimes people make enormous errors that go undetected for decades, centuries, or nearly an entire millennium before anyone picks up on them, despite the fact that they're painfully obvious. We're not sure what exactly the following stories say about mankind, other than that none of us really know what we're doing.
#5. The Spanish Mistake California for an Island for 200 Years
Yep, for a couple of centuries, maps looked like this:
California's an island. Oregon and half of Canada don't exist. Mapmaking was a little more relaxed on the West Coast.
California is a fairly large landmass, big enough that you'd think no one could ever possibly confuse it with an island. Standard procedure for charting an island presumably includes "drive your boat all the way around the damn thing to make sure it isn't landlocked," and any explorer trying to mark that item off on their California checklist would notice that the Golden State is connected to the entirety of North and South America. Heck, you could stand on the coast looking east with a telescope and figure out that the Pacific Ocean doesn't make another appearance at any point in that direction.
Like most creatives, Columbus got lazy in the last stretch.
However, during the early days of the European explorers, nobody bothered to do any of those things, because there were native peoples to rob and murder, and proper cartography simply would've taken too much time. After all, priceless religious artifacts don't melt themselves down into Spanish doubloons. Consequently, California was incorrectly drawn as an independent landmass for over 200 years.
You see, California was first charted in 1533 by Fortun Ximenez, a mutineer who broke off from Hernan Cortes' original Aztec-busting fleet. Ximenez took his stolen ship north along the Pacific coast of Mexico, and wound up landing in Baja. He decided that he and his rebellious shipmates had just discovered the Island of California, despite the fact that there was absolutely no evidence to suggest that the land he'd just stumbled upon was actually an island. Also, the Island of California was a fictional place from a famous Spanish novel, which by definition would make it difficult to locate in a hijacked galleon. At any rate, Ximenez had no time to retract or amend any part of his declaration, because he was promptly killed by natives.
"Ooooh, take us ashore near all those friendly looking natives!"
After receiving word from the survivors of Ximenez's crew, Cortes took some ships up to Baja himself and backed up the mutinous lunatic's claim that California was indeed an island separate from the continent they had just beaten the ancient shit out of, most likely because Cortes wanted to establish a new colony he could call dibs on governing.
The Spanish government supported Cortes (as it usually did) and had a ton of maps drawn up with this hilariously flagrant error. As a result, maps all over Europe showed California as an island, including those four random and completely nonexistent lesser islands in between California and the mainland that somebody threw in there for no conceivable reason. Other explorers, such as Juan de Fuca, continued visiting California, but they kept finding inlets they didn't want to travel down. Rather than waste their time doing any actual exploring, they would all simply announce "Yep, it's totally still an island" and go on their merry way.
Inlets? You must mean the fingers of Satan.
California kept getting copied and pasted into new maps this way for decades, until finally, in 1776, a Spanish explorer named Juan de Anza decided to literally walk from Texas to California to prove everyone wrong and correct the mistake, because it wasn't like there was anything else particularly important going on in North America at the time.
#4. Des Moines Is Accidentally Named After a Native American Poop Joke
Des Moines, currently the capital of Iowa, takes its name from the nearby Des Moines River, which was christened by the French explorers Marquette and Joliet specifically because they liked how French the name sounded. You see, during their travels, Marquette and Joliet encountered the Peoria tribe and asked them what the name of the river was. The Peoria told them "Moingoana," which kind of sounds like "moines," the French word for "monks." So they took to calling the river "les Moines," which eventually became "Des Moines," which eventually became the capital of Iowa.
Ah, Des Moines. Sounds classy! Right? Right?
The problem is, "Moingoana" means "shitface." And nobody bothered to check up on that, ever, at any point. Considering how the colonization of America went down in general, it isn't too surprising that deciphering the meaning behind a Native American phrase wasn't high on anyone's list of priorities, but you'd think somebody would've at least thumbed through a pocket translator before slapping the name on their capital city.
You see, the Peorians misunderstood Marquette and Joliet's question. They thought the two Frenchmen were asking who else lived in the river valley, not the name of the river itself. The Peoria tribe had a good trading relationship with France at that point and didn't want to be replaced by a neighboring tribe, so the Peoria chief cunningly told the two explorers that the only other tribes who lived in the area were total shitfaces.
"Oh man, they're totally buying it! Shut up, shut up, nobody tell them what it really means!"
Despite the fact that by all accounts Marquette understood the Peoria language, he didn't seem to notice, and so the mighty Shitface River flowed through middle America until the 1800s, when the bustling metropolis of Shitface sprang up along its banks. Incredibly, no one properly translated the name until 2003, but by that point it was a little late to change it.
#3. Paris Is Unwittingly Built Above Flimsy Mining Tunnels
If you've ever studied the skyline of Paris, like maybe during that scene where it gets destroyed by an asteroid in Armageddon, you might have noticed that the central part of the city has virtually no tall buildings. Seems odd for a bustling European metropolis, right? Well, that's because nobody can build much of anything in Paris without the city collapsing into the earth, thanks to a chaotic maze of unmapped tunnels dug underneath it.
If your city's tallest building was built in 1889, there might be something wrong with your city.
Gypsum and limestone had been mined beneath Paris since the 13th century. As the city grew, so did the tunnels, but nobody bothered to keep track of how many were being dug or how far they extended in any particular direction, because civil engineering is more fun that way. A handful of Parisian suburbs were swallowed up by subterranean mine shafts over the next few centuries, and by the 1700s entire sections of Paris were dropping through the ground like the Name of God challenge from Indiana Jones and the Last Crusade.
City officials were appropriately baffled, as none of them had any idea that Paris was essentially sitting on top of a giant ant farm full of unrefined minerals and the skeletons of the poor.
How many times do you French need to be told? Skulls aren't a sound building material!
King Louis XIV sent some men to investigate why the earth was eating their city, and they discovered that pretty much all of Paris was in danger of collapsing, as it was built atop miles and miles of fragile quarries that, once again, nobody had bothered to keep track of. Improvements to the tunnels were immediately begun, but despite the numerous catastrophes, France continued boring dangerous holes beneath its capital city until the late 1800s.
The Arc de Triomphe looks less impressive underground.
The French government finally got wise to the fact that they were essentially digging Paris a giant grave in the 1950s, and since then almost all of the tunnels have been declared off-limits. The city has weight restrictions imposed on buildings to keep from putting too much strain on the threadbare mine shafts beneath them, hence Paris' lack of skyscrapers. However, with sections of the tunnels still regularly collapsing, all it will take is a small tremor or a medium-sized Luc Besson-produced explosion to bury the whole city like S.H.I.E.L.D. headquarters.