Illustration of an下沉式庭院 in a campus

Quick answer：

A sinking courtyard in a campus refers to a courtyard that is located below the level of the surrounding ground. Such designs often incorporate green spaces, water features, and other amenities to create a serene environment within the campus. They can serve as relaxation areas, recreational spots, or aesthetic elements. In architectural design, sinking courtyards are used to enhance privacy, reduce noise, and provide a unique spatial experience.