Ibiza was declared a UNESCO World Heritage Site in 1999 for both its cultural and natural significance. The document discusses the four areas that led to this designation - Dalt Vila, Necropolis de Puig des Molins, Phoenician settlement of Sa Caleta, and Posidonia. It provides details about each site, including descriptions, histories, and pictures. A variety of events that take place on the island each year are also outlined, such as sporting competitions, medieval fairs, fashion shows, music festivals, and film festivals.