Clerestory (or clearstory) window
A row of windows placed high on the walls of churches, cathedrals, or other large buildings, allowing natural light to enter from an elevated angle. Positioned above eye level, these windows help illuminate deep interior spaces more effectively. In church architecture, clerestory windows are often installed at the uppermost part of the nave walls to take advantage of the height difference between the nave and side aisles. See also high window.