Siena Cathedral, interior of nave including dome on hexagonal base completed by ca. 1270; vaults raised late 13th? After 1355?. Commissioned by the Operai of Siena Cathedral.

Siena Cathedral, interior of nave including dome on hexagonal base completed by ca. 1270; vaults raised late 13th? After 1355?. Commissioned by the Operai of Siena Cathedral.