city, Niigata ken (prefecture), Honshu, Japan, in the Kashiwazaki plain, facing the Sea of Japan. During the Tokugawa era (1603–1867), it was a post town on the Hokuriku-kaidō (Hokuriku Highway), which was known as the transportation route of gold from Sado Island to Edo (now Tokyo). Oil refineries were established in the city in the early 20th century, following the opening of the Nishiyama oilfields and the construction of two railways. Other products include machinery, industrial glass, and lumber. Kashiwazaki is also a resort, known for its hot springs. Pop. (2005) 94,648.