title: Grand Canal (China)
context: The Grand Canal, known to the Chinese as the Beijing–Hangzhou Grand Canal (Jīng-Háng Dà Yùnhé), a UNESCO World Heritage Site, is the longest as well as the oldest canal or artificial river in the world.[1] Starting at Beijing, it passes through Tianjin and the provinces of Hebei, Shandong, Jiangsu and Zhejiang to the city of Hangzhou, linking the Yellow River and Yangtze River. The oldest parts of the canal date back to the 5th century BC, but the various sections were first connected during the Sui dynasty (581–618 AD). Dynasties in 1271-1633 significantly rebuilt the canal and altered its route to supply their capital Beijing.
question: What is the longest canal in the world?
answers: Grand Canal