The Dubrovnik–Neretva County is the southernmost Croatian county, located in south Dalmatia. The county seat is Dubrovnik and other large towns are Korčula, Metković, Opuzen and Ploče. The Municipality of Neum, which belongs to neighbouring Bosnia and Herzegovina, divides the county in two parts.
The southern part of the county consists of Dubrovnik and the surrounding area, including the Pelješac peninsula, and the islands of Korčula, Lastovo, Mljet, Šipan, Lopud and Koločep. The northern part of the county includes the Neretva Delta, the Baćina lakes north of Ploče, and a swath of hinterland near the southernmost slopes of Biokovo and around the hill of Rujnica.
Although the 9 kilometres-long stretch of coast belonging to Neum effectively makes the southern part of the county an exclave (disconnecting it from mainland Croatia) it is still connected with the rest of the country via territorial waters. Road traffic going to and from Dubrovnik through Neum is usually less subject to customs controls in order to reduce the traffic congestion. The road connecting Dubrovnik to the rest of the country via Neum has one lane per direction and bus lines passing through Neum often make rest stops there so that passengers can take advantage of lower Bosnian taxes and purchase tobacco and alcoholic beverages as they tend to be cheaper there.
The Croatian and Bosnian governments are planning to build an expressway that would connect Dubrovnik through the Neum municipality and would not require any border control. The regional government of the county is also planning to build a sea bridge at Komarna that would directly connect the southern tip of the northern part of the county to the Pelješac peninsula (the Pelješac bridge), thereby linking the southern part of the county as well.
The northern part of the Mljet island is a national park. The Lastovo archipelago is a designated nature park. The southernmost tip of the county is the demilitarized Prevlaka peninsula at the border with Montenegro.