Distribution of the deepest and longest caves in the Western Tatra Mts.: 1. a, b - Bandzioch Kominiarski, 2. Jaskinia Zimna, 3. Jaskinia Czarna, 4. Jaskinia Wysoka-Za Siedmiu Progami, 5. Jaskinia Mietusia, 6. Studnia w Kazalnicy Mietusiej, 7. Ptasia Studnia-Lodowa Litworowa, 8. Jaskinia Kozia, 9 Jaskinia Wielka Sniezna: a. Sniezna, b. Nad Kotlinami, c. Jasny Aven, d. Wielka Litworowa, 10. Sniezna Studnia. The Krakow-Wielun Upland (Wyzyna Krakowsko Wielunska) This is the largest karst region in Poland. It occupies about 2500 km2. Nowadays there are more than 1500 known caves in this area. Almost all of them are developed in Upper Jurassic limestones. Only a few are situated in Lower Carboniferous limestones and Middle Triassic limestones and dolomites. Jaskinia Wierna, which was explored in 1990 is the longest cave in the Krakow - Wielun Upland. It is about 1020 m long. The caves of this area are mainly horizontally developed, the deepest is Jaskinia Studnisko -75 m deep. Some caves are situated inside protected areas (i.e. the Ojcowski National Park and Jurassic Landscape Parks). The access to these caves requires special permission. Five caves are open for tourists and four of them are lit by electricity. The Swietokrzyskie Mts. (Gory Swietokrzyskie) In recent years the most significant exploration success outside the Tatra Mts. took place in this area. It was the linking of Chelosiowa Jama with Jaskinia Jaworznicka in spring 1996. The new system, developed in Devonian limestone, is 3670 m long. Although the system is now at the ninth place on the list of the longest Polish caves, other of 140 caves occurring in this area are rather small. Only two of them are longer than 100 m. The most known is Raj cave, famous for well developed speleothems. This cave is open for tourists and equipped with electricity. The Nida river basin (Niecka Nidzianska) It is the only one of non carbonate karst areas in Poland. Almost all of 50 caves situated in this region are developed in Miocene deposits, mainly in gypsum and only subordinately in kalkarenites. The longest is Jaskinia Skorocicka (about 190 m). The Sudety Mts. (Sudety) Most of karst caves in the Sudety Mts. are developed in Precambrian and Palaeozoic marbles. Apart from them some karst caves are situated in Permian limestones. Other caves, these of non karst origin, occur in granites and sandstones. There are known more than 70 caves in the discribed mountains. The famous one is Jaskinia Niedzwiedzia, which is the longest (2230 m) in the Sudety Mts. The upper part of this cave is open for tourists. The deepest cave of this area is Szczelina Wojcieszowska with vertical extent 112 m (+19, -93). Other caves in Poland Some caves in Poland are situated outside of the above characterized regions. Two caves are developed in Pleistocene sands near Gdansk in northern Poland. Other small caves, which represent probably exhumed fossil karst, are known from Jurrasic limestones quarries near Inowroclaw in central Poland. A few caves were discovered during mining the zinc-lead ores in the Olkusz area north-west of Krakow. These caves are developed in Middle Triassic dolomites. Similarly small caves in Miocene rock salt in famous Wieliczka mine (south of Krakow) were discovered during mining. These caves are called Krysztalowe Groty (Crystal Caverns) due to the halite crystals occuring on their walls. Acknowledgment The morphometric data of cave mentioned in the text were derived from many sources. Some of them have already been published in the eight volumes of inventory of Polish caves. Six of them were edited by J. Grodzicki and discribe some of the Tatra caves, the other two - Swietokrzyskie Mts. caves (edited by J. Urban) and the Sudety caves (edited by M. Pulina). The publications by A. Amirowicz, J. Baryla, K. Dziubek & M. Gradzinski on caves in the Pieniny National Park, by M. Szelerewicz & A. Gorny on caves in the Cracow - Wielun Upland, by G. Klassek on the Beskidy caves, by W.W. Wisniewski, by R.M. Kardas, as well as by M. Tomaszek were also used. The geological data about distribution of karst features in Poland were based on the articles by J. Glazek, T. Dabrowski & R. Gradzinski (1972), as well as by J. (Glazek, R. Gradzinski & M. Pulina (1982). I was also provided with some personal information by A. Antkiewicz (about Ptasia Studnia cave) and G. Albrzykowski (about Sniezna Studnia cave) who are gratefuly acknowledged.