The main body of the cathedral was originally built in Roman times as Diocletian’s mausoleum. An octagonal structure made of massive stone blocks and ringed by 28 granite and marble columns, it was converted into a church by refugees from Salona in the 7th century. The cathedral’s massive wooden doors, protected by glass, are the work of 13th-century sculptor Andrija Buvina, who decorated them with carvings depicting scenes from the life of Christ. Inside, the 15th-century altar of St. Anastasius was created by architect Juraj Dalmatinac, who also designed Šibenik Cathedral and Pag Town. The cathedral treasury displays a bewildering horde of gold and silver, including reliquaries containing the body parts of various saints. It is also possible to climb the bell tower for amazing views down onto the Old Town and out to sea. Because of its central location within Diocletian’s Palace, the Peristil (peristyle) in front of the cathedral is a popular public meeting place, just as it was in Roman times.