Cerknica (Circonio, Zirknitz ) is a town in the Karst region of southwestern Slovenia, with a population of 4,018 (2016 census). It is the seat of the Municipality of Cerknica. It belongs to the traditional region of Inner Carniola.
Cerknica was first attested in written sources as Circhinitz in 1040 (and as Czirknicz in 1145, Cyrknitz in 1261, and Cirnizza in 1581). The name is derived from *Cerkvnica, a univerbation of *Cerkvna (vas) 'church village'. A church was established very early in Cerknica, probably already in the 9th century. The original structure was burned down in an Ottoman attack in 1472.
