At present there are 114 karst abysses on our planet with the depth of more than 1000 m. 21 out of them are located in Spain, 17 - in Austria, 17 - in Italy, 9 - in Mexico, 9 - in Georgia, 9 - in Slovenia, 8 - in France, etc. An absolute world record was established when the record depth of more than 2 km (2212 m) was overcome in the Veryovkina Cave (Abkhazia, Georgia) on the limestone massif of Arabika.
On the territory of high mountainous Bzypi limestone massif there are two abysses with a depth of more than 1000 m (Illyuzia-Mezhonnogo-Snezhnaya, 1760 m and Shakhta Vjacheslav Pantjukhina, 1508 m), which are listed among the deepest speleoobjects of the world and occupy respectively the 5nd and the 13th places.
The cave systems of Napra, Pionerskaja and Grafsky Proval (Bzypi ridge) approach the thousands of meters threshold, the depth of which respectively are 970, 815, 770 m.