Foiba (Italian plural foibe) is the name adopted to define deep natural sinkholes common in the Kras (Carso) region, a karstic plateau region shared by Italy, Slovenia and Croatia. The name is derived from the Latin fovea (chasm); they are indeed chasms excavated by water's erosion, have the shape of an inverted funnel, and can be up to 200 meters deep. Such formations number in the hundreds in Istria.
This name, especially in Italy, is commonly associated to mass killings perpetrated by Yugoslav partisans during and shortly after World War II against ethnic Italians, Fascists and other real or perceived enemies.