Floor-level sunken courtyard plan

Quick answer：

A floor-level sunken courtyard plan is a design for a courtyard that is sunken below the ground level of a building. It is typically used to create a private, secluded outdoor space that is partially or entirely enclosed. These courtyards often incorporate various architectural elements such as walls, pergolas, or raised areas to enhance privacy and aesthetics. They are commonly found in residential or commercial buildings where a serene and secluded outdoor environment is desired.