That's in the Mall of America, largest of its kind in the country. So there's more room than one would think, and the place really is a big tourist attraction.
Merlin recently BOUGHT the Mall of America's Aquarium ("Underwater Adventure"), which has been modestly successful from a business perspective but is a very mediocre experience for anyone familiar with good aquariums.
I will resist the temptation to launch into an analysis of the merits of Kensyian economics vs. the "free market" here, but I think it is safe to say the Merlin-owned Aquarium has not--and will continue NOT to have--even the slightest positive educational or environmental value.