Hidden in a bend of the Mississippi River just south of New Orleans, 29 concrete bunkers lie on a grid of dirt and grass roads. Some hold remnants from the past — 40-year-old gas masks and biohazard signs still hang on a wall. Most of them have been abandoned for decades. But inside two of those bunkers, 15 million fish eyes stare at the walls through the glass of their jars. This is the Royal D. Suttkus Fish Collection, the largest collection of preserved fish in the world, and almost no one knows it exists.