The Shell Museum stands out for its unique shell-inspired exterior. A 5-meter-long reconstructed model of a chock shell, the ancestor of the nautilus shell, which is a representative shell of the Orbis period sea about 500 million years ago, is displayed in the center of the pavilion. Visitors can experience the beauty of the ancient sea.

The oceans occupy about 70% of the entire earth. Shellfish are said to be the most diverse species in it. Around Japan alone, there are approximately 8,000 species of shellfish. The Shell Museum is marked by a building that looks like a large bivalve shell. It constantly displays about 5,000 specimens of about 1,500 species and ecological exhibits.

The museum also has the world's largest bivalve mollusk, the Ojacogai, whose shell weighs 194 kg, on display, as well as a 3D theater and other visual learning materials that enable visitors to learn about shells. Other exhibits include a special exhibit on the ecology of clione, ichneumon, and other species, and an exhibit of ammonite fossils, which are representative of Hokkaido.