The shell mounds had been known to the local people for a long time.
In 1877, the American zoologist Edward S. Morse (who would later teach zoology at the University of Tokyo) came to Japan, and, on the second day of his arrival while riding Japan's first railway from Yokohama to Tokyo (founded in 1872), "found" these mounds and instantly felt their importance.
Dr. Morse with his assistants later excavated these mounds from the Jōmon Period and published his paper in 1879, which launched Japan's modern archeology.
The shells, pottery, and other items that Dr. Morse excavated are mostly stored at the University Museum of the University of Tokyo and are Japan's Important Cultural Property.
The Ōmori Shell Mounds are located within five-minutes' walk from the north entrance of Ōmori Railway Station of the JR Keihin–Tōhoku Line.