Dubrovnik ( formerly Ragusa) is a Croatian city on the Adriatic Sea. It is one of the most prominent tourist destinations in the Mediterranean Sea. In 1979, the city of Dubrovnik joined the UNESCO list of World Heritage sites. The prosperity of the city was historically based on maritime trade; as the capital of the maritime Republic of Ragusa, it achieved a high level of development, particularly during the 15th and 16th centuries, as it became notable for its wealth and skilled diplomacy. In 1991, after the break-up of Yugoslavia, Dubrovnik was besieged by Serbian and Montenegrin soldiers of the Yugoslav People's Army (JNA) for seven months and suffered significant damage from shelling. After repair and restoration works in the 1990s and early 2000s, Dubrovnik re-emerged as one of the top tourist destinations in the Mediterranean.