A rainbow has appeared above the awe-inspiring Hukou Waterfall on the Yellow River, Linfen City, Shanxi Province, creating an amazing spectacle. Hukou Waterfall is situated on a section where the river narrows like the mouth of a kettle. Upstream, the Yellow River is 300 meters wide, but within the space of just 500 meters, it is compressed to just 20-30 meters in width. Here, water cascades more than 20 meters down a cliff face. Hukou is China's second largest waterfall and the world's largest yellow waterfall.