foiba

thumb|Grotta Plutone is a foiba close to Basovizza, Trieste ([[Italy)]]

A foiba (from Italian: ; plural: foibe or foibas)—jama () in South Slavic languages scientific and colloquial vocabulary (borrowed since early research in the Western Balkan Dinaric Alpine karst)—is a type of deep natural sinkhole, doline, or sink, and is a collapsed portion of bedrock above a void. Sinks may be a sheer vertical opening into a cave or a shallow depression of many hectares. They are common in the Karst region shared by Italy and Slovenia, as well as in the karst of the Dinaric Alps in Bosnia and Herzegovina, Montenegro, and Croatia. The foibe massacres, a war crime that took place during and after World War II, take their name from the foibe.