Karlovac is a city and municipality in central Croatia. According to the National census held in 2011 population of the settlement of Karlovac was 55,705. Karlovac is the administrative centre of Karlovac County. The city is located on the Zagreb-Rijeka highway and railway line, 56 kilometres (35 miles) south-west of Zagreb and 130 km (81 miles) from Rijeka.
Croatians know Karlovac as grad parkova (the city of parks) and grad na četiri rijeke (the town on four rivers) for its numerous green areas and four rivers, of which Mrežnica, Korana, and Kupa flow through built-up areas, and Dobra is a few kilometers outside the city centre. A documentary film made by Dušan Vukotić in 1979 on the occasion of the 400th anniversary of the founding of the city plays much on that theme, and shows pictures of happy bathers on the Korana's Fogina beach (Foginovo kupalište) in the city centre.
One of the rarer trees found in the parks is the Ginkgo biloba, which local primary school children are taken out to see as part of their classes on nature and society. Most of the parks are planted in the former trenches dug around the old military fort that were once filled with water as an added layer of protection from the marauding Ottoman armies. One part of the city centre maintains the name of Šanac ('trench') after the old trenches which preserve the old hexagonal form of the historic centre.