Cathedral of St. Domnius
The main body of this cathedral is the 3rd-century-AD octagonal mausoleum designed as a shrine to Emperor Diocletian, and a peek inside and a trek up to the bell tower are well worth the views. During the 7th century, refugees from Salona converted the space into an early Christian church. Its interior contains a hexagonal Romanesque stone pulpit from the 13th century with rich carvings, and the elegant, 200-foot-tall Romanesque-Gothic bell tower was constructed and reconstructed in stages between the 13th and 20th centuries. Climb to the top of the bell tower (sometimes closed in winter and during bad weather) for a spectacular view of the entire palace, Split, and the surrounding Adriatic Sea.