History is riddled with mysterious, unexplainable events. There are some things that even modern day scientists and anthropologists can only theorize about. Here is a list of top five strange historical events that no one seems to have a sure answer about:

5. Dancing Plague of 1518

In 1518, 400 people danced themselves to death. Literally. It all began in July of that year when Frau Troffea began to violently dance down the streets of her hometown, Strasbourg in France. It is said that there was no music playing and that she didn’t look at all joyous. Neighbors soon joined in and within a week, 30 people were dancing all day nonstop. By the end of the month, 400 people were affected. Eventually, each of these dancers died from heart attacks, exhaustion, or strokes. There are several theories surrounding the origin of this plague, the most popular being that the dancers were in a state of stress-induced psychosis. Their community had suffered severely from famine, and the area was riddled with diseases like smallpox and syphilis. The stress of that time is said to be so intolerable, that a mass psychological illness came about in the form of the Dancing Plague. Strange theory, right? How is it that hundreds of starving people managed to dance for days when normal people would get exhausted in hours? What kept them alive? Why did this occur? No one truly knows.

4. The Stone Spheres of Costa Rica

Discovered during the 1930’s, the stone spheres of Costa Rica are a vast collection of around three hundred nearly-perfect polished orbs of stone sculpted from granodiorite, an igneous rock similar to granite. These orbs range from a few centimeters to over two meters in diameter, and can weigh up to 16 tons. The exact date they were created is unknown, but some hypothesize that they were carved between 200 BC and 1600 CE. Their function or purpose is also unknown. Several myths have been created about them, such as they came from Atlantis or were made by nature. Local legends even tell stories about ancient native inhabitants who had access to a potion able to soften rocks, yet no evidence of such has been found. Interestingly, the stone spheres were often placed in clusters of up to 20 and were often found in geometric patterns like triangles, rectangles or straight lines. It has been pointed out that such alignments can sometimes be associated with pointing toward the Earth’s magnetic north.These stones were clearly crafted by very skilled sculptors. However, the ancient Costa Ricans had no written language. So it is unlikely we will ever know the truth behind these spheres.

3. Creation of the Easter Island Heads

The Easter Island Heads are quite popular and known for being created by ancient Polynesian people called the Rapa Nui. These great stone sculptures are stone blocks carved into head-and-torso figures that average around 13 feet (4 meters) in height and 14 tons in weight. Though scholars are unable to explain the meaning and use of the structures, known as moai statues; it is assumed that the statues may have been used for religious purposes, and or to honor ancestors, chiefs, or other important personages. Sadly, there is only oral history that tells stories of the mysterious inhabitants of Easter Island, who are said to have been overtaken by some environmental catastrophe of their own making. No one truly knows what they're over nine hundred statues were built for.

2. The Great Vowel Shift

During the Middle Ages, the British speakers of English changed nearly all vowel pronunciations over the short span of 1-2 generations. This change affected the long vowels in English, meaning that a vowel that used to be pronounced in one place in the mouth would be pronounced in a different place, this time, higher up. Why this occurred is a mystery. It is quite a sudden and drastic advance that has influenced the way we pronounce words in English today. What caused the change?

1.The Creation of Gobekli Tepe

Situated in Urfa, an ancient city in Turkey, is what appears to be the world’s oldest temple, Gobekli Tepe. It was built around 12,000 years ago, circa 10,000 BC. In this extraordinary site are T-shaped pillars, which are said to represent human beings, with carved animals (like foxes, snakes, boars, cranes, ducks, and lions) and abstract symbols etched into the stones. What’s interesting is that each pillar weighs anywhere from 40 to 60 tons, which leaves us unable to explain how this incredible feat was accomplished. 12,000 years ago, even the simplest of hand tools were hard to come by. Who created them? How did they get those stone blocks there? How did they carve those designs? In a period, we thought only consisted of roaming hunter-gatherers, how and who managed to create such a complex, well-preserved temple? What would they worship in the temple? There are so many unanswered questions about this amazing site, the most important of which being: Do we have to change our vision of how and when civilized human history began?

These are only some of the unexplainable events present throughout history. Reading about them makes me wonder just how much we don’t know about the past. What phenomena were our ancestors unable to record? Will we ever uncover the secrets behind these historical, mysterious events? Perhaps someday we will, but for now, they remain missing pieces in the grand puzzle that is our past.

To learn more about the unusual events mentioned, visit: "Mystery explained? 'Dancing Plague' of 1518, the bizarre dance that killed dozens," "Easter Island - Facts & Summary," "Costa Rica Stone Spheres," and "Gobekli Tepe: The World's First Temple?"