Visitors take photos of icicles at the Hukou Waterfall scenic spot of the Yellow River at the border area between north China's Shanxi Province and northwest China's Shaanxi Province on Dec. 7, 2018. (Xinhua/Lyu Guiming)
A visitor takes photos of icicles at the Hukou Waterfall scenic spot of the Yellow River at the border area between north China's Shanxi Province and northwest China's Shaanxi Province on Dec. 7, 2018. (Xinhua/Lyu Guiming)
People visit the Hukou Waterfall scenic spot of the Yellow River at the border area between north China's Shanxi Province and northwest China's Shaanxi Province on Dec. 7, 2018. (Xinhua/Lyu Guiming)
Visitors take photos of icicles at the Hukou Waterfall scenic spot of the Yellow River at the border area between north China's Shanxi Province and northwest China's Shaanxi Province on Dec. 7, 2018. (Xinhua/Lyu Guiming)