The National Aquarium in Baltimore continues to be the most visited attraction in Maryland. Bring a friend to see its collection of 16,500 specimens representing 660 species. Particular attractions include the dolphin display, rooftop rainforest, central ray pool, and multiple-story shark tank. The National Aquarium in Baltimore is widely considered to be one of the best in the United States, if not the world. Coastal Living named it the #1 aquarium in the U.S. in 2006.