The Ice Aquarium uses flash-freezing technology to preserve fresh fish unloaded in Kesennuma's port on the Pacific Ocean. Inside, the ambient air is a cool minus 5 degrees F (minus 20 C), and guests have to don parkas to keep warm. The difference between the temperature inside and outside the aquarium can sometimes top 50 degrees Celsius.
Okamoto Seihyo, a manufacturing company in Kesennuma, northeastern Japan, helped produce the Ice Aquarium displays. It specializes in what it calls "ice art." Its craftsmen can freeze everything from salmon to bottles of sake to flower arrangements. These are all presented in cylinders of ice that are given as gifts.