Arafuna Fukeana

Overview

Arafuna Fukeana, located in Shimonita Town, Gunma Prefecture, is a "fukeana" (naturally ventilated cave) used during the Meiji era to store silkworm eggs (kaiko-shu). Fukeana, known for their cool breezes even in summer, were sometimes used for storing pickles in the Edo period. Temperature control is crucial for preserving silkworm eggs, making fukeana ideal storage locations. Arafuna Fukeana was constructed by the father-son team of Niwa Seitaro and Niwa Chishu. Seitaro served as village head and prefectural assembly member, while Chishu, a graduate of Takayama-sha Sericulture School, gained knowledge of fukeana in Nagano during his studies. Chishu surveyed the area around his home, focusing on a fukeana 7km from his residence, assessing its suitability for silkworm egg storage. Arafuna Fukeana consists of three fukeana: the first completed in 1903 (Meiji 36), the second in 1908 (Meiji 41), and the third in 1913 (Taisho 2). Experts such as Honda Iwajiro, director of the Tokyo Sericulture Training Institute, and Machida Kikujirou, president of Takayama-sha, collaborated on the construction of these storage facilities. Arafuna Fukeana was exceptional in scale. Before the completion of the third fukeana, a 1909 (Meiji 42) survey indicated a storage capacity of 1.1 million silkworm eggs—far surpassing the next largest facility in Gunma Prefecture, Haruna Fukeana, with only 100,000. Arafuna Fukeana played a pivotal role in enabling multiple annual silkworm harvests, contributing significantly to the development of Japan's modern industry, alongside the Tomioka Silk Mill. In 2014, it was registered as a component of the World Heritage site, "Tomioka Silk Mill and Related Sites," recognizing its historical value globally. Today, only the fukeana remain, but the surviving structures evoke the former grandeur, offering a palpable sense of history. Visitors should be mindful of their clothing, the near-total lack of cell phone reception, and the possibility of encountering bears or snakes along the path.