The so-called Baltic Sea anomaly refers to a sonar image discovered on the seafloor that sparked theories of a crashed UFO, ancient structure, or unknown object. Over the years, it became one of the internet’s favorite mysteries.
More recent scientific explanations suggest it is most likely a natural geological formation shaped by glacial activity during the last Ice Age, rather than anything artificial.
This video breaks down the original discovery, the most popular theories, and what modern analysis actually indicates about the object.