Rácskai Cave

Rácskai Cave is one of the highly protected caves of Hungary. It is located in the area of the Buda Mountains within the Danube–Ipoly National Park. Among the caves of the Buda Mountains, this cave yielded the first palaeontological find of a vertebrate animal that lived before the Pleistocene.

Description

The entrance of the cave lies in a non‑cultivated stone quarry on the outskirts of Remeteszőlős, not far from Budapest, on Hosszúerdő Hill, in front of the northern entrance of the Remete Gorge, on the right side. The cave entrance is a roughly 50 m long concrete (reinforced concrete) shaft. The cave was formed in Triassic Dachstein limestone due to the corrosive effect of thermal waters.

The mineral deposits in the cavity are varied. It contains gypsum, cauliflower, calcium sheet, logomit (i.e., gypsum column), cave Christmas‑tree remnants and stalactites. Hydrothermal solution forms, spherical concretions and flowstone draperies can also be observed on its walls. It has two entrances and consists of a large hall. Its horizontal extent is 50 m. The sealed cave can be visited only with permission from the Danube–Ipoly National Park and with the use of electric lighting. It is mainly of interest to specialists as a very damaged cave. The cave can be traversed with basic caving equipment. According to data from the Danube–Ipoly National Park Directorate, the planned route of variant A of the western sector of the M0 motorway, between highway 10 and highway 1, approaches the cave at a distance of 10–35 m around the 90 km kilometre mark.

The cave, located not far from the Rácski settlement, also known as the Rácskai settlement, was named after it. In the literature the cave occurs under the names Rácskai-II. cave (Elkis SK 1973), Rácskai-II cave (Elkis SK 1973), Rácskai-quarry No. 1 cave (Kordos 1984), Rácskai-quarry No. I cave (Házi 1977), Rácskai-quarry cave (Kordos 1979), Rácskai settlement No. I cave (Házi 1977) and Rácskai-settlement Quarry No. 1 cave (Kraus 2003). In 1993 the cave was first called Rácskai-cave in the literature.

Research history

The cave opened in 1973 during stone mining. Hubert Kessler explored it on 27 August 1973, surveyed the cave, and then, using the survey data, drew the cave plan map sketch, the longitudinal section map sketch and the cross‑section map. The Elkis SK speleologists drew the plan map and longitudinal section map of the cave named Rácskai-II. cave in that year. This cave is probably the Rácskai-cave. The Imre Vass Cave Exploration Group surveyed the cave in 1977, and then Tibor Domokos, using the survey data, prepared the cave plan map. Sándor Kraus collected in 1979 from the cavity a Pliocene white‑toothed hamster tooth, which László Kordos identified. The book *Caves of Hungary*, published in 1984, includes the cave in the national cave list (Rácskai-quarry No. 1 cave) located in the Budai Mountains. Associated with the list is a 1:500 000 scale map showing the geographic location of the caves of the Danube‑Zug Mountains, indicating the cave’s geographic position.

The Barlangtani Department edited the cave plan map and cross‑section maps in 1985. According to the survey data, the cave is 10.7 m long, 3.2 m deep, its entrance is 1.4 m wide and 1.05 m high. According to the cave cadastral register sheet of the Rácskai Cave dated 10 February 1985, the Rácskai Cave has a horizontal extension of 32 m. After 1985 the now‑inactive stone mine began to be filled with waste. Several research groups also tried to explore unknown parts of it, but achieved no particular success. In the information booklet of the 1987 MKBT central research camp there is a figure showing, among the Buda caves, how high, e.g. the Rácskai Cave is situated in terms of tszf. height, and what the vertical extension of these caves is. The Acheron Cave Research Department surveyed the cave in 1989 and then, using the survey data, prepared the cave plan map. According to the survey, the cave is 60 m long.

The SZIKKTI Cave Exploration Group carried out conservation work in it in 1992. From April 8, 1993, according to the Ministry of Environment and Regional Development decree 12/1993. (III. 31.) KTM, the Rácskai Cave in the Buda Hills is a specially protected cave. It became a specially protected cave because of its geological significance and endangerment. The group carried out exploratory work in the cave in 1997. In August 1998 the cave plan map and length‑section map were completed, edited by Zoltán Szabó. The maps were drawn using the data from the cave survey conducted by Zoltán Szabó, Péter Szabó and Gábor Újvári. From May 14, 1998, according to the Ministry of Environment and Regional Development decree 13/1998. (V. 6.) KTM, the Rácskai Cave located in the Buda Hills, within the jurisdiction of the Danube–Ipoly National Park Directorate, may be visited with the directorate’s permission.

Attila Nyerges prepared maps of the cave entrance surroundings in July and September 2001. From May 17, 2001, according to the Ministry of Environment decree 13/2001. (V. 9.) KöM, the Rácskai Cave located in the Buda Hills is a specially protected cave. At the same time the provision 1/1982. (III. 15.) OKTH concerning the determination of the circle of specially protected caves loses effect. According to the book *Hungary’s Specially Protected Caves* published in 2003, the cave’s length is 100 m, vertical extent 34 m, depth 31 m, height 3 m and horizontal extent 50 m. The 2003 report of the Anubis Cave Exploration Department states that on the terminal wall of the mine of the Hosszúerdő‑hegy rock cavity a fine‑structured, laminar calcite deposit was visible, which is known from the Rácskai Cave.