1Zhengyan Pools
In China's Huanglong Valley, more than 650 colorful pools form a series of terraces down a mountainside, separated by natural walls of mineral deposits. Thousands of years ago, mineral-rich water began flowing down the mountainside, leaving behind deposits of calcium carbonate that gradually hardened into stone. As these deposits accumulated, they formed raised walls that trapped water and created hundreds of natural pools. Differences in water depth, minerals, and light give the pools their striking shades of blue, green, and yellow.


