There are many UNESCO World Heritage Sites on the Dalmatian Coast. Perhaps the most famous of these is Dubrovnik’s historic walled old town. Originally erected to protect the city from invaders, now the walls provide a picturesque vantage point from which to view the city and its environs. Diocletian’s Palace, located near the busy harbor in Split, was built in the 4th century for the Roman emperor, and retains its historic importance because it's the most complete Roman palace in the world. Located not far from Split, the historic town of Trogir earned its UNESCO designation based largely on its architecture.