Illustration of a sunken courtyard with a ceiling

Quick answer：

A sunken courtyard with a ceiling, also known as an underground courtyard, is a type of courtyard design where the courtyard is located below the ground level. It is often used in modern architecture for creating a private, serene space. An illustration of such a courtyard would typically show the layout of the space, including the ceiling structure, walls, and any decorative elements. This type of design can help to insulate the building from outside noise and provide a cooler environment in hot climates.