A former refrigerator for silkworm eggs.
Arafune Cold Storage is the remains of a chilling facility utilizing cold air blowing from between gaps in rocks to keep silkworm eggs cold. Construction on the site began in 1905. At the time, it boasted the largest storage capacity in Japan. Buildings were constructed atop piled rocks and silkworm eggs were stored underground, where even in summer, interior temperatures were maintained at around 2ºC. Whereas previously silkworms could only be reared once a year in the spring, these temperatures allowed delaying hatching and permitted hatching multiple times during the year. Additionally, communication and transportation were established to facilitate responding to requests from throughout the country, and this contributed to the growth of cocoon production throughout Japan. The development of Arafune Cold Storage was further assisted because it could be accessed for transport from Shimonita Station on the Kozuke Railway (now Joshin Electric Railway), which had just opened.
The role of Arafune Cold Storage ended with the development of electric refrigeration technology, and the site closed around 1935.
Even now, if you put your hand inside, you can feel the cold air.