CHURCH OF SANTA MARIA ASSUNTA (CATHEDRAL) (15th century) The church of Santa Maria Assunta known as the Cathedral or Duomo has been built on the ruins of the ancient parish church visible on the facade. It is one of the oldest if not the oldest church of the city. It was constructed at the dawn of the age of Christianity, perhaps in the 4th century, on the foundations of a pagan temple. Its actual form is due to constructions that took place in the second half of the 14th century according to some designs attributed to Giuliano da Sangallo. Immediately after the new construction, the church was declared the Diocesan Cathedral in place of the church of San Vincenzo, located outside the walls. The central doorway and the side door are both works by Cristofanello (16th century). The main altar was created in 1664 by Francesco Mazzuoli of Cortona