Pócsakő Sinkhole

The Pócsakői water sink is among the specially protected caves of Hungary. It is located in the Aggtelek National Park. Together with the other caves of the Aggtelek Karst and the Slovak Karst, the cave is part of the World Heritage. It is one of the six specially protected caves of Bódvaszilas.

Description

It is located on the edge of the Upper Hill plateau, northwest of the centre of Bódvaszilas. Unlike the potholes characteristic of the Upper Hill plateau, it is a periodically active water sink cave, just like the Meteor cave and the 2nd water sink cave on the Kopaszgally side. About 100 metres from the latter there is a hole‑like entrance in a water sink funnel. It lies directly beside the National Blue Trail route, next to section number 24 of the National Blue Trail. Approached from the centre of Bódvaszilas, it opens after a steeply rising road section.

The water that is absorbed in the cave emerges at the Vecsem spring, which is 2100 metres away in a straight line. It formed in Upper Triassic limestone. Its passages are debris‑filled and narrow, and the cave is poor in dripstones. A permit and basic caving equipment are required for exploration. It is recommended to use a rope for climbing in the lower shaft, for which a 10‑metre rope is sufficient.

The cave occurs in the literature under the names Pócsa‑kő Cave (Kordos 1977), Pócsa‑köi‑water‑sink cave (Vlk 2019), Pócsa‑kői‑cave (Kőrösi 1983), Pócsakői‑cave (Szenthe 1972), Pócsakői‑water‑sink cave (Kordos 1978), Pócsa‑kői‑water‑sink cave (Takácsné 1987), Pócsakői‑water‑sink cave (Kordos 1977) and Pócskői‑water‑sink (Kordos 1984). In 1984 the cave was first called Pócsakői‑water‑sink in the literature.

Research history

Members of the Budapest Red Meteor Caving Research Group began to explore the cave by digging in 1963, and in the summer of 1963 they managed to reach a depth of 20 m. In March 1964 they demonstrated the connection between the water sink and the Vecsem spring with fluorescent water dye. The water painted on March 24 appeared in the spring six days later. The distance between the cave and the spring is about 2 km in a straight line. In the summer of 1964 the group's cavers discovered additional passages in the Pócsakői‑water‑sink, whose length at that time was about 50 m.

Gábor Frojimovics and his colleagues continued their exploratory work in the cave in 1965. At that time, under the leadership of Gábor Frojimovics, the cave was surveyed. Using the survey data, the cave's plan map and length‑section map were produced. In his field report of September 1965, György Dénes wrote regarding the survey that the cave's length was 90 m and its depth 51 m. The group carried out a smaller verification and work in the passage system in 1966. Researchers of the VMTE Petőfi Group worked at the Pócsakő water sink end point in 1968 to discover additional passages. Members of the MHSZ Debrecen Light‑Diving Club Cave Research Group and members of the VMTE László Lakatos Cave Research Group performed mapping work in the cave in the mid‑1970s.

In the manuscript written by Károly Bertalan, completed in 1976, it is mentioned that the Pócskő water sink (Pócsakő water sink) is located on Alsó‑hegy, Bódvasziláson. The approximately 30 m long cave’s painted water emerged at the Vecsem spring. The water sink conducts water from very steep sides, therefore water flows quickly into the sink. The part of the manuscript describing the cave was written based on one publication. From the English‑language special issue of Karst and Cave of 1977, the report titled The longest and deepest caves of Hungary (December 31, 1975) it can be learned that the 51 m deep Pócsa‑kő Cave (water‑sink cave) lying in the Aggtelek Karst was, on December 31, 1975, the 41st deepest cave in Hungary. The 40th deepest cave (Nagykőmázsa‑oldali‑zsomboly) is also 51 m deep.

According to the state on December 31, 1977 (MKBT Invitation May 1978), the Pócsakői sinkhole on the Aggtelek Karst, 51 m deep, is the 46th deepest cave in the country. Based on the compilation published in the 1977 Karst and Cave, on December 31, 1977 Hungary’s 50th deepest cave is the Pócsakői sinkhole located on the Aggtelek Karst, 51 m deep on December 31, 1977, 1976 and 1975. The 49th deepest cave (Nagykőmázsa‑oldali‑zsomboly) is also 51 m deep. This compilation is more up‑to‑date than the list published in the MKBT Invitation of May 1978.

In the Pócsakői sinkhole the VMTE Central Cave Research Group carried out exploration work in 1981, 1982, 1983 and 1984. In 1982 the Red Meteor TE Central Cave Research Group had a research permit for cave investigation. In the 1984 book *Caves of Hungary* the national cave list includes the cave on the Aggtelek Karst under the name Pócskői‑sinkhole with the variant name Pócsakői‑sinkhole. Associated with the list is a 1:500 000 scale map showing the geographic location of the caves of the Aggtelek Karst and the Bükk Mountains, indicating the cave’s geographic position. According to the state on December 31, 1987 Hungary’s 62nd largest vertical‑extent cave is the Pócsa‑kői‑sinkhole cave, with a vertical extent of 51 m, among the 5 450 cave‑cadastral units. According to the compilation, the depth list published in the 1977 Karst and Cave states the cave is 51 m deep.