Listed as a World Heritage Site in 2014, Tomioka Silk Mill provides a look at the history of silk production, with some English-language narration. Completed in 1872, the mill was once one of the world's largest producers of silk. Today, its buildings are some of the only Meiji-era government factories preserved in excellent condition. It makes a fascinating day trip from Takasaki. To get here take the Joshin Dentetsu line to Joshu Tomioka Station, then walk 10 minutes.