Pamukkale is composed of Pamuk (cotton) and Kale (castle). Cotton is white as cotton and looks like cotton ball from a distance. It is actually a hard limestone terrain. Castle is that it is composed of the whole hillside, layer by layer, shaped like a castle, so it is named Cotton Castle. There are many hot springs here. The hot springs flow down from the top of the cave and wash the slopes into ladders. The spring water on the platform is stored and becomes a pond. People can sit and soak in the hot springs. Minerals in the spring water settle down and dye the whole hillside white, like open-air karst. From the top down, on the one hand, the hot spring platform is like a mirror, reflecting the blue sky and white clouds; from the bottom up, like a newly erupted volcano, white magma covers the entire slope, quite spectacular. The formation of cotton fort is precisely due to the continuous outflow of underground hot spring water from the ground, which contains rich minerals.