Risnjak is situated in Gorski Kotar, the most dense forest part of Croatia, in the immediate vicinity of the sea, covering an area of 3,014 hectares. The park covers the middle part of the Risnjak complex, spreading from the source of the Kupa river to Gornje Jelenje and Crni Lug to Snjeznik. Its tallest summit is Veliki Risnjak, 1,528 m tall and is considered to be one of the most beautiful in Croatia. The summits of Mali Risnjak are vertical like walls, and the most beautiful part is the mountain range Bijele Stijene with their bare cliffs.
The inner park zone features a great number of magnificent natural developments of remarkable beauty due to which this area is ranked in the highest degree of nature preservation. In 1949 botanist Ivo Horvat suggested for the first time that the area around Risnjak should be protected. On his advice, the parliament of the then Republic of Croatia declared 36.00 km² around Risnjak to be a national park. Snježnik is the second highest peak in the park (1506 m). The mountain should not be confused with Snežnik, a peak 20 km to the north-west in Slovenia.
On its grassy peak is located a mountain lodge called Albaharijev dom. It is about 1.5 hours' walk from the ski resort of Platak; this has made it the most common place for tour skiing in Croatia. The wild and torn mountain contains well developed karst formations: gullies, precipices, potholes and karst depressions hosting varied vegetation and animal species. All the plants and animals in the Risnjak national park are protected by law.