In 2015, the aquarium had 2.02 million visitors. It was the most visited aquarium in the U.S. in 2005, and in 2007, it surpassed the Field Museum as the most popular cultural attraction in Chicago. The aquarium contains 1,500 species, including fish, marine mammals, birds, snakes, amphibians, and insects. The aquarium received awards for "best exhibit" from the Association of Zoos and Aquariums (AZA) for Seahorse Symphony in 1999, Amazon Rising in 2001, and Wild Reef in 2004. It was designated a National Historic Landmark in 1987.