Dome

A dome is an architectural element shaped like the hollow upper half of a sphere, closely related to the cupola, though the exact boundary between the two terms is debated among historians. A dome can rest directly on a circular wall, on a drum, or on a system of squinches or pendentives that make the transition from a square or rectangular room below to the round or polygonal base the dome needs above. Domes appear across a very long architectural lineage, built in ancient Mesopotamia and found in Persian, Hellenistic, Roman and Chinese building traditions as well as in Byzantine and Sasanian architecture, which shaped later domed building in both Europe and the Islamic world through the Middle Ages. European Renaissance builders spread domed construction from Italy from the early modern period onward, and Baroque and Neoclassical architects drew directly on Roman precedent. Materials used for domes over the centuries range from mud, snow, stone and wood to brick, concrete, metal, glass and plastic, and domes today cover religious buildings, legislative chambers and sports stadiums alike.