Physically, county is divided into three main parts: elevated hinterland (Dalmatinska zagora) with numerous karst fields; narrow coastal strip with high population density; and the islands. Parts of the Dinaric Alps, including Dinara itself form the border with Bosnia and Herzegovina while Kozjak, Mosor and Biokovo mountains separate the coastal strip from the hinterland.
The county is linked to the rest of Croatia by the newly built four-lane Split-Zadar-Karlovac-Zagreb highway and the Lika railway. Split-Kaštela international airport is used mostly by tourist charter flights in the summer. There is also a smaller paved airfield on the island of Brač.
In the hinterland, larger towns are Sinj (pop. 11,500 town, 25,373 with villages), Imotski (4,350) and Vrgorac (2,200).
Besides the largest city, Split (189,000 city proper, 240,000 including Kaštela and Solin), towns on the coast are Trogir (11,000), Omiš (6,500) and Makarska (13,400).
On the islands, settlements are smaller due to high emigration, but mostly urban in character. Among them are Supetar (3,000) on the island of Brač, Hvar (3,700) and Stari Grad (1,900) on Hvar and Vis (1,800) and Komiža (1,500) on Vis.
According to the 2001 census, Split-Dalmatia County has population of 463,676. Croats make up an absolute majority with 96.30% of the population.
Dalmatia became part of the Roman province of Illyricum. In 9 AD the Dalmatians raised the final of a series of revolts together with the Pannonians, but it was finally crushed, and in 10 AD, Illyricum was split into two provinces, Pannonia and Dalmatia which spread into larger area inland to cover all of the Dinaric Alps and most of the eastern Adriatic coast. Dalmatia was the birthplace of the Roman Emperor Diocletian, who constructed Diocletian's Palace in the core of what is now present day Split.
Split-Dalmatia County is divided:
The county assembly is composed of 51 representatives, organized as follows: