Two feet in thickness. Visitors will have several opportunities to watch all of these spectacular species with 4,574 square feet of viewing windows, a 100-foot-long underwater tunnel, 185 tons of acrylic panes, and one of the largest viewing windows in the world at 23 feet tall by 61 feet wide and 2 feet thick. The aquarium was built for about $14 million in 1982. At that time, it was the most expensive single structure ever erected in the state of Georgia. It is now ranked number two behind only the High Museum of Art in Atlanta. The aquarium has received numerous awards for its design and construction. It takes about 200 pounds of fish to produce a pound of seafood. In other words, eating fish is an efficient way to help save our oceans. Fish are also high in protein but low in fat and sodium. Fish are part of every culture, religion, and cuisine on Earth. They have been used for food since at least 700 B.C. when Chinese historians record their emperor cooking up a feast featuring carp. Even today, China remains the largest consumer of fish. In North America, fish are popular as well. We like them fried, broiled, or smoked. We also use them in stocks, soups, and stews. Fish are so important to humanity that they have been used as currency, as collateral, and even as security against loans.