The term 穹顶 refers to a dome structure, often found in architecture. It is a curved roof or ceiling that is typically hemispherical in shape. Domes can be made from various materials, including concrete, glass, and metal, and are commonly used in buildings like churches, mosques, and government structures. In addition to their aesthetic appeal, 穹顶 serves practical purposes, such as providing structural support and allowing for spacious interiors. Famous examples include the 圣彼得大教堂 in Vatican City and the 清真寺 in Istanbul, both showcasing the beauty and engineering of dome architecture.