It's been 80 years since aviator Amelia Earhart disappeared during her solo voyage around the world, but the mystery of her fate persists today. The first woman to fly across the Atlantic, Earhart attempted in 1937 to become the first woman to fly around the world. After covering thousands of miles, she disappeared with her plane somewhere over the Pacific Ocean. Despite years of investigations, she was never found.

At least, that's how the story goes. Despite theories that she was captured by Japanese troops or faked her death to go live in New Jersey, the evidence makes it clear her death was more prosaic. Last fall, the International Group for Historic Aircraft Recovery (TIGHAR) announced they found evidence Earhart made radio transmissions for days after her plane went missing, suggesting that she either landed safely or survived the plane crash. Either way, it seems she called for help. Furthermore, the remains of a woman with a similar stature to Earhart were found on a Pacific island in 1940. There's no way to tell for certain yet, but it looks like Earhart died a castaway.

Back in 1959, a group composed mostly of college students hiked into Russia's Ural Mountains. Months later, their bodies were found six miles away from their intended destination, Mt. Ortorten, and about a mile away from their campsite on the side of Kholat Syakhl.

Russian investigators concluded that six had died from hypothermia and three from injuries. Two hikers were found with major skull damage, and two more had major rib fractures. One woman was missing her tongue, and a few others were found without eyes. Their tents were torn open from the inside, and everyone was inadequately clothed for the blizzard that took place the night they died. Police were unable to find evidence of any foul play; the only footprints at the scene appeared to be those of the hikers.

It's enough to make anyone believe in yetis, but there's actually a fairly reasonable explanation for each oddity. The physical trauma was most likely caused by an avalanche, and the strange clothing (or lack thereof) was likely "paradoxical undressing," which is known to happen in extreme hypothermia. The missing body parts can be chalked up to scavenging animals. Not so scary now, is it? Or, well, maybe it still is... but for different reasons, at least.

Sometimes known as the Devil's Triangle, the Bermuda Triangle is roughly located between Florida, Puerto Rico, and Bermuda. Supposedly, ships and aircraft entering its nebulous boundaries shouldn't expect to make it out alive. Following the disappearance of an entire Navy squadron in the area in 1945, dozens of unexplained disappearances have been attributed to its waters.

Explanations have ranged from aliens to the slightly-more-plausible methane bubbles, but last fall, meteorologists pointed to a simple explanation: bad weather. Apparently, strange cloud formations can be found over the area, and these hexagonal shapes can create sudden, extremely powerful air currents that could send a plane crashing into the waves or capsize a boat.

Centered around modern-day Guatemala, the Mayan civilization peaked in the first millennium. It was a highly sophisticated society, with a complicated calendar and system of writing — but sometime during the 8th or 9th centuries, many Mayan cities declined rapidly until their previously-crowded cities were reclaimed by the environment. Although the Mayan people still live today, the civilization essentially collapsed.

Historians have been trying to figure out what caused the decline for quite some time; theories include overpopulation, revolution, and aliens. (Obviously.) In 2012, however, researchers from Arizona State University analyzed archaeological data and suggested that the collapse probably stemmed from the environment. According to their findings, there was a severe drought and rapid deforestation in the Yucatan peninsula around the time of the collapse. Such conditions usually lead to erosion and soil depletion, which in turn makes farming difficult. In the end, the Maya had to abandon the lowlands to avoid starvation.

In the town of Homestead, Fla., there lies a mysterious stone sculpture garden called Coral Castle. The structure was built over the course of nearly 30 years by a single man, Edward Leedskalnin, who cut and shaped more than 1,100 tons of coral rock using only hand tools, despite his small stature. The resulting structure is a feat of engineering, featuring a water fountain, sundial, and a nine-ton gate so perfectly balanced it can be moved with a finger. The Coral Castle Museum's website compares it to the Taj Mahal and ancient pyramids.

For years, Leedskalnin's creation, which he built singlehandedly, has baffled visitors. Some claim he used levitation to build Coral Castle, while others believe he utilized magnetism. But in reality, Leedskalnin was simply a hard worker with an understanding of leverage. As Live Science explains, "Though the quarried stone slabs are large, they are actually lighter than they appear because the rock is porous." Leedskalnin used tools like winches and pulleys, which are on display at the museum. One of his friends, Orval Irwin, even wrote a book explaining exactly how the Coral Castle was built — no metaphysical activity required.

On June 30, 1908, the air above a remote part of Siberia exploded. The fireball flattened 80 million trees and exploded windows in a town more than 35 miles away, sending some residents flying off their feet. Although no human died, hundreds of reindeer were killed by the blast. No crater was ever found.

For decades, scientists (and some UFO enthusiasts) tried to explain what came to be known as the Tunguska event, named for a nearby river. Theories ranged from the formation of a miniature black hole to a low-flying alien spaceship. These days, however, most researchers agree that in all likelihood, the source of the explosion was an asteroid or comet. The lack of a crater, combined with the appearance of a fireball in the sky, suggests that the object exploded in the atmosphere before it could reach land, and the resulting "air burst" is what flattened the area below.

Everyone knows the story: On the night of July 16, 1917, the Romanov family was executed in Yekaterinburg, Russia, by revolutionaries. In the years following their deaths, however, rumors began circulating that the youngest daughter, Anastasia, or her brother had survived, protected from the bullets by jewelry sewn into their clothing. Numerous women even came forward claiming to be Anastasia, keeping the mystery of her fate alive for more than a century afterward.

The reality, however, is rather less romantic. Although DNA testing of the primary Romanov grave initially showed no evidence that Anastasia had been buried there, scientists later tested the remains found in a second, nearby grave found in 2007. Sure enough, in 2009, bone fragment analysis concluded that the bodies in the second grave were indeed Anastasia and her brother, Alexei. Their survival was simply too good a story to be true.