Common structural elements in buildings around the globe, domes were first constructed atop primitive huts using sticks and mud. Their full architectural potential was not realized, however, until the 6th-century Byzantine architects of Constantinople’s Hagia Sophia perfected the use of pendentives—triangular sections of vaulting that form the transition between circular domes and their polygonal supporting structures. Not all domes are perfectly circular. When was the first oval dome built? Discuss
Source: The Free Dictionary