Chicago's Shedd Aquarium is an indoor public aquarium. When it opened in 1930, it held five million gallons of water and was the world's largest indoor facility; it was also the first inland aquarium with a permanent saltwater fish collection. Today
it contains 1,500 species, including fish, marine mammals, birds, snakes, amphibians, and
insects. In 1987 the Shedd was designated a National Historic Landmark.