Sunken courtyards are a traditional architectural element in some Asian cultures, particularly in Japan and China. They are designed to be lower than the surrounding ground level and are often used for relaxation, meditation, or as a garden space. The term 'natural' implies that the courtyard is not artificially constructed but integrates with the natural landscape. Pictures of natural sunken courtyards typically showcase serene, traditional designs with elements like stone lanterns, stepping stones, and water features.