3. Bloop

In 1997, the U.S. National Oceanic and Atmospheric Administration (NOAA) repeatedly recorded a sound in an autonomous underwater recording station. West of the Southern tip of South America, it was described as it “rises rapidly in frequency over about one minute and was of sufficient amplitude to be heard on multiple sensors, at a range of over 5,000 km.” It’s incredibly loud and deep, but even weirder it matches the types of sounds usually associated with living creatures, despite being many times louder than any known organism. A number of people associated with the research firmly believe that it’s neither man made or geologic in nature, instead an animal that we’ve not previously identified. The place the sound was located? A mere 950 nautical miles from the sunken city of R’lyeh…just saying.