Summarize the characteristics of a Zen rock garden

Quick answer：

Zen rock gardens, also known as karesansui, are Japanese rock gardens characterized by simplicity and minimalism. They typically include raked gravel or sand to represent water, a few carefully placed rocks to symbolize mountains, and often a small bridge or island. These gardens emphasize the beauty of natural elements in a serene and tranquil setting, aiming to evoke a sense of peace and contemplation.