The Arian Baptistery is located in Ravenna and was built at the time of the Ostrogothic king Theodoric, starting from the end of the 5th century, completed shortly after, in the first half of the 6th century. It was the baptistery of the ancient Arian cathedral, now called the Church of the Holy Spirit. Since 1996, the baptistery has been included in the list of Italian World Heritage List by UNESCO, within the serial site "Early Christian Monuments of Ravenna".