The Baltimore Aquarium, located in Baltimore, Maryland, houses more than 660 different species of marine animals, and contains more than 16,500 specimens. It is open Mon.-Thurs.: 10 a.m. – 4 p.m. Fri.: 10 a.m. – 8 p.m. Sat. and Sun.: 10 a.m. – 5 p.m. You can avail coupons and deals to save on your visit.