Gravel used in the dry landscape of the karesansui

Quick answer：

Karesansui, also known as Zen rock garden, is a Japanese rock garden that uses gravel, sand, and sometimes pebbles to represent a natural landscape. The gravel is used to create ripples that mimic water in traditional Zen gardens, symbolizing the sea or a river. The choice of gravel can vary, with different sizes and colors used depending on the desired aesthetic and the scale of the garden.