The Adriatic coast of Croatia
Diocletian’s Mausoleum was built in 305 CE and constructed like the rest of Diocletian’s Palace with high-quality white local limestone and marble. It became part of the Cathedral of Saint Domnius, consecrated at the turn of the 7th century and regarded as the oldest Catholic Cathedral in the world that remains in use in its original structure.
Photo by Ludo Kuipers, Mon Aug 09, 1965