Baradla-tetői Pothole

The Baradla-tetői-zsomboly has been one of Hungary's specially protected caves since 1993. It is located in the Aggtelek National Park. Together with the other caves of the Aggtelek Karst and the Slovak Karst, the cave has been part of the World Heritage since 1995.

Description

On the Baradla-tető at the edge of Aggtelek, north of the summit, in a forest, on the edge of a sinkhole, on a strongly karstified surface, in a specially protected area, about 100 metres from the Eger-zsomboly, in the sinkhole in which the Eger-zsomboly also opens, there is a vertical, north‑south oriented, split entrance measuring 0.6 × 0.9 metres and closed with an iron door. It is located to the left of the tourist trail marked with a blue triangle that starts from the main entrance of the Baradla cave in Aggtelek. The location of the cave is indicated on tourist maps by the name Baradla-tetői-zsomboly.

In middle Triassic Wetterstein limestone, dissolution occurred along ENE–WSW‑oriented fault lines. It consists of stepped, parallel shafts, whose characteristic features are tectonic, planar surfaces. In places, stalactite columns, ledges, stone slabs, arches, dissolution channels, draperies, flowstones, and pea‑stones have formed. The largest cavity is the 20 × 5 metre Rom chamber, which is practically a collapse labyrinth. Most of the speleothems are found in the chamber and the corridor leading to it, for example varied‑colour draperies about 10–20 centimetres long. The endpoint at a depth of 87 metres is in fissure number 1. The deepest point of fissure number 2 is at a depth of 83 metres.

Based on measurements they calculated that the pothole is approximately 600 metres in a straight line from the Baradla Cave’s Lebanon Hill, and that the level of the Baradla Cave stream could be reached by sinking the deepest point by about 50 metres. The cave can be visited with the permission of the Aggtelek National Park Directorate, by persons experienced in rope techniques, using technical equipment and electric lamps.

The cave also occurs in literature under the name Baradla-tető Shaft (Takácsné, Eszterhás, Juhász, Kraus 1989).

Research history

On 11 April 1986 the cave was discovered by three speleologists of the Eger Alpine Club, Tamás Kutás, László Fekete and Béla Bertók, by a very drafty collapse that lasted only a short time. In the same year the research was joined by the Rózsadomb Kinizsi Cave and Mountaineering Sports Association led by Péter Adamkó, and the members of the two groups together reached the deepest point, where a strong airflow could be felt. On 20 September 1986 Ádám Katapán performed carbon‑dioxide and temperature measurements at the bottom of the entrance shaft and the farther shafts of the main fissure. At that time no draft was detectable anywhere. It was closed in 1986.

In April 1987 members of the Rózsadomb Kinizsi Cave Exploration and Mountaineering Sports Association and the Eger Alpine Club surveyed the cave, then Pál Borka, based on the survey, prepared the cave floor plan map, longitudinal section map and two cross‑section maps. On the floor plan map, which indicates the east direction for its use, the locations of the two cross‑sections in the cave can be seen. The maps present the cave at a scale of 1:100. According to the survey the cave is 307 m long and 87 m deep. Based on the condition as of 31 December 1987, the Baradla‑tetői‑zsomboly, with a vertical extent of 87 m in the 5430 cave cadastral unit, is Hungary’s 34th largest cave by vertical extent. The 35th largest cave by vertical extent (Szeleta‑zsomboly) also has a vertical extent of 87 m. According to the compilation, the Baradla‑tetői‑zsomboly is not listed in the depth list published in the 1977 Karst and Cave bulletin. The cave’s vertical extent was determined based on the 1987 survey (Rózsadomb Kinizsi SE). In 1989 members of the MÁFI Cave Exploration Group conducted speleogenetic observations in the pit.

The 1989 compilation titled Karst and Caves, Caves of Hungary mentions that outside the Lower Mountain, the pothole cave type is less characteristic in other parts of the Aggtelek Karst, and therefore the discovery of the Baradla‑tetői pothole attracted great attention. This pothole is located only 400 m from the Baradla cave, above it. The 87 m deep pothole was discovered in 1986. In figure 2 of the publication (Aggtelek and Jósvafő area) the cave’s geographical location is shown. The English‑language version of this later study (The caves of Hungary) appeared in the 1989 special issue of the journal. In this study Baradla‑tető Shaft is the name of the cave. A list was published together with the English‑language study, listing the deepest caves of Hungary. According to the list, the 89 m deep Baradla‑tetői pothole (Baradla‑tető Shaft) lying in the Aggtelek Karst was the 34th deepest cave in Hungary in 1988.

In 1990 the MÁFI Cave Research Group had a research permit for the cave. The March–April 1993 MKBT Programme Book reported that the KTM Nature Conservation Office planned the publication of a poster series featuring the specially protected caves of Hungary and was looking for students for it. Posters are being prepared about the specially protected caves of the Aggtelek Karst and about caves that will become specially protected in the near future, including one depicting the Baradla‑tetői pothole. This cave was also marked with a star, which means that it is primarily sought after for photographs.