Final answer:
Croatia is the country that includes the city of Split and the UNESCO World Heritage site of Dubrovnik, which are significant cultural landmarks reflecting the region's rich history.
Step-by-step explanation:
The country that has the city of Split and the UNESCO world heritage site of Dubrovnik is Croatia. After the breakdown of Communism and the death of Yugoslav leader Josip Broz Tito in 1980, Croatia, along with several other provinces, declared independence from Yugoslavia. This resulted in the breakup of Yugoslavia and the establishment of Croatia as an independent nation. Dubrovnik, known for its well-preserved historical center, and Split, home to the Diocletian's Palace, are both significant cultural landmarks that reflect the rich history of the region.