The trunks all bend toward the ground in the same direction, extending three to nine feet, before curving upward and stretching toward the sky, taking the shape of an upside-down question mark. But almost a century after the 400 pine trees were planted in what is now known as Poland's Krzywy Las, or Crooked Forest, the reason for the deformity remains a mystery, reports the New York Times. Officials in the nearby town of Gryfino believe the trees were warped seven to 10 years after they were planted in the 1930s, reports Weather.com. But, perhaps because Gryfino was destroyed in World War II, no record of the trees or reason for the shape has been uncovered, leading to theories ranging from heavy snowfall to witchcraft, per Business Insider.
Others believe the trees may have been flattened by German tanks during the war. But as the crooked trees only appear on less than an acre in a larger forest, that seems unlikely, per Weather.com. Genetic mutations have been known to warp other trees, including in Canada's Crooked Bush. However, such trees don't suddenly grow smooth and straight after curving only at the base, as those in the Crooked Forest have done, an expert tells the Times. Most are comfortable assuming that farmers bent the trees in the hope that they could use their wood for ship building, as Gryfino lies just 50 miles from the Baltic Sea. But whatever the truth, the trees are now a tourist hot spot—and, according to the Huffington Post, an "interesting" spot to have sex. (Read more Poland stories.)