In 2011, Marine biologists manufactured a baffling discovery—over 1,300 virtually perfect circles scattered across the Mediterranean Sea floor off the coast of Corsica. These formations, some 67 toes broad, sparked a great number of theories: have been they volcanic craters, WWII bomb scars, or a little something even stranger? https://medium.com/@perfectseoservice2017/the-thriller-of-one-three-hundred-best-circles-on-the-mediterranean-seafloor-science-unveils-the-f6327a72d07b