Koper is a city in southwestern Slovenia, with the other Slovenian coastal towns Ankaran, Izola, Piran, and Portorož, situated along the country's 47-km (29-mile) coastline, in the Istrian Region, approximately five kilometres (3.1 miles) from its border with Italy. Having a unique ecology and biodiversity, it is considered an important national natural resource. With only one percent of Slovenia having a coastline, the influence that the city's Port of Koper, which is also the major contributor to the economy of the eponymous city municipality, has on tourism was a factor in deciding Ankaran to leave the municipality with a referendum in 2011. Koper is the main urban center of the Slovenian Istria with a population of about 25,000.
The city of Koper is officially bilingual, with both Slovene and Italian as official languages.