Sanmenxia Dam is the engineering project most closely tied to the modern city’s identity. Built across the Yellow River, it was one of the early large-scale water-control schemes of the People’s Republic, and its ambitions and controversies both belong to the story.
The dam is most interesting if you care about China’s river engineering, not as a scenic attraction alone. Combine it with the wider Yellow River landscape and the city’s museums to understand why Sanmenxia exists where it does.