 Having assisted King Helü in planning modern Suzhou (then known as "Helü City"), Wu is also sometimes credited as the culture hero responsible for the invention of the waterwheel.Some Chinese believe that the Dragon Boat Festival, celebrated on the fifth day of the fifth lunar month and usually associated with the poet Qu Yuan, actually commemorates the death of Wu Zixu, whose body was thrown into a river near Suzhou after his forced suicide.The story of Wu Zixu is prominent in Sima Qian's "Records of the Grand Historian", where it is used as a foil of the author's own choice to accept castration for the sake of a greater goal instead of having chosen honorable suicide.