The New England Aquarium first opened to the public in 1969. A main feature of the aquarium is a four story, forty-foot diameter salt-water tank. The tank is so large, it had to be built first, before the rest of the aquarium was built around it. The tank is home to several species of salt water fish, sharks, and sea turtles, including Myrtle who weighs 550 pounds. The aquarium also has a state of the art medical facility for injured sea animals. The New England Aquarium’s IMAX theater is 85 feet wide and 65 feet tall.