Sunken courtyard

Quick answer：

A sunken courtyard, also known as a sunken garden or sunken patio, is a type of garden or outdoor living space that is lower in elevation compared to the surrounding area. It often features a central water feature, such as a pond or fountain, and is surrounded by plantings, seating areas, and pathways. This design element creates a sense of privacy and intimacy, as well as offering a visually appealing contrast to the surrounding landscape.