Youli Castle Site is one of Anyang's older historical excursions, connected with the story of Ji Chang, later remembered as King Wen of Zhou. Tradition says he was imprisoned here by the last Shang ruler and, during that captivity, worked out the sixty-four hexagrams associated with the Classic of Changes.
The site is not as visually overwhelming as the Yin ruins, but it gives useful context for Anyang's deep pre-imperial history. Go for the story rather than for grand surviving architecture: the value is in standing at a place where Chinese political legend, divination, and early state history overlap.