Sunken courtyards in residential buildings are a design feature that creates a more intimate and private space within the confines of a building. These courtyards are typically located below ground level and are surrounded by residential units or other structures. They can serve various purposes such as providing a quiet retreat, enhancing aesthetics, or offering a space for gardening. The design of such courtyards often involves careful consideration of lighting, ventilation, and integration with the surrounding architecture to ensure functionality and aesthetic appeal.