The light well is an architectural solution for bringing natural light and fresh air into parts of a building too far from the external façade. It is especially relevant in densely built urban areas and deep-plan buildings. Light wells can be open at the top or glazed, ranging from simple incisions to elaborate atrium structures. In 19th-century residential construction, they were essential for illuminating rear rooms. Modern high-rises use light wells as architectural design elements that simultaneously improve energy efficiency. Dimensioning depends on depth, the reflective properties of wall surfaces, and the desired quality of daylight.