Gorski kotar is located in the western part of Croatia between Lika and Slovenia. Its northern border starts at the source of the River Čabranka and stretches along the Čabranka and Kupa rivers to the village of Zdihovo Bosiljevsko. This is also the historical border with Slovenia. In the north-east, the border stretches from the source of the River Čabranka via Prezid, Čabarska Polica and the western slopes of Mount Obruč to Klana. This is a historical, natural and ethnic border.
The border clearly marks the transition between the barren littoral landscape and the wooded mountainous area.
To the east, the border of Gorski kotar runs beside the valley of Ogulin-Plašće from Severin na Kupi to Krpelj, past the plain of Ogulinsko polje to the village of Ogulinski Hreljin, and then continues along the slopes of the Klek mountains and Modruško zagorje to the village of Modruš.
The south-eastern border is a wide transitional zone. It encompasses the areas between the Rudolfina and Jozefina roads – there areas are referred to as the Drežnica or Kapela regions. The main feature of this zone is its karst soil overgrown with high forests.