This excep­tion­al sys­tem of lime­stone caves com­pris­es col­lapsed dolines, some 6 km of under­ground pas­sages with a total depth of more than 200 m, many water­falls and one of the largest known under­ground cham­bers. The site, locat­ed in the Kras region (lit­er­al­ly mean­ing Karst), is one of the most famous in the world for the study of karstic phe­nom­e­na.