Illustration of a narrow and sunken courtyard

Quick answer：

A narrow and sunken courtyard is a design feature often found in traditional Asian architecture, particularly in Japan. It typically consists of a small, enclosed space that is lower in elevation than the surrounding area. This type of courtyard is used for various purposes, including meditation, relaxation, and as a transition between the indoors and outdoors. The illustration would typically show the courtyard with elements such as stepping stones, lanterns, and plants to create a serene and harmonious atmosphere.