Siena Cathedral (Italian "Duomo di Siena", officially Santa Maria Assunta) is a Cathedral in Siena, Italy. It is the seat of the archbishop of Siena. The cathedral was built between 1215 and 1263. The was another church there beforehand. The Cathedral is known all over Italy for its "stripes". These were made by using different kinds of stone. It is also a unfinished building as well.