The Island of Krkis in the Bay of Kvarner or Quarnero. It is the biggest island in the Adriatic, with an area of 409.9 square kilometres. The highest peak is Obzova, at 569 m. There are some twenty little islands, islets, rocks and reefs around the main island: Prvic,  Galun, Zec, Plavnik, Kormati, Kosljun and Sv. Marko (St Mark's).

The seven historical castles of the island are today its seven administrative centres: the city of Krkand the communes of Omisalj, Malinska, Punat, Baska, Vrbnikand Dobrinj.