Tomioka Silk Mill is a long, low brick building with a timber frame, and it looks stranger than it is. In 1872, only a few years after the Meiji government opened Japan to the West, the state built this factory to produce silk by modern methods and sold it abroad to pay for the country's modernisation. A French engineer, Paul Brunat, designed it and hired French instructors, and the brick, laid in a pattern known as Flemish bond, was made locally by workers who had never seen a brick building before. The cocoon warehouses, with their sturdy roof frames, are still among the biggest wooden-framed brick buildings in Japan.
Many of the first workers were young women from samurai families, and they brought home what they learned to train others across the country. Silk was Japan's most important export through much of the late nineteenth and early twentieth centuries, and the mill remained in operation until 1987. Gunma prefecture was a heartland of silk farming, and you will see old farmhouses with raised roof ventilators designed for raising silkworms. Mulberry trees, the food of the worms, are still grown here, and the hills around the town produce konnyaku and good vegetables.
The ride to Tomioka crosses the Kanto plain toward the Myogi range, a jagged cluster of rock towers and forested ridges that rises behind the town, and the road gets curvier as it climbs. Winter brings a dry, cold wind called the karakkaze that sweeps across the plain from the mountains, and can be bitingly cold. Summer is hot and humid. Roads here are in good condition, though narrow in the older parts, and parking at the mill is straightforward.
Tomioka has nearly fifty thousand people, so petrol stations and restaurants are easy, and you will find soba shops and cafes near the mill. The site opens daily with a ticket, and guides can be booked. The nearby Myogi Shrine, with its dramatic rock setting, and Haruna and Akagi mountains are good for a longer ride. Autumn colour brings crowds to the hills, so choose weekdays if you can.