Mainz - the capital of Rhineland-Palatinate is a university town on the left bank of the Rhine opposite the mouth of the river Main. It was an archbishopric and ecclesiastical center as well as an electorate. The most dominant landmarks of the city center are the six spires of St. Martin's Cathedral. Its construction began in 975, and it was rebuilt, especially in the 11th to 13th centuries. Much of the original Romanesque architecture still remains. It represents one of the finest church buildings in the Upper Rhine region. St. Stephen's Church is another architectural highlight.