Arany Hole

The Arany-lyuk is among the specially protected caves of Hungary. It is located in the Pilis Mountains in the Danube–Ipoly National Park. Of the 16 caves located in Budakalász, the Arany-lyuk is the deepest. It also appears in tourist guidebooks.

Description

Along the ridge trail marked with a red stripe that starts from Csillaghegy and leads to Nagy-Kevély, north of the road, a few meters away, in Budakalász, on the mountain ridge, in a rocky and bushy area, on the side of the Silver Saddle facing Nagy-Kevély, the entrance opens. It is located on the right side of the tourist path, after the trail marked with a red square joins it. Next to the entrance there used to be a small doline about 10 meters in diameter and seven meters deep, collapsed, at the bottom of which a small inactive water sink opened.

The entrance to the shaft is a three‑meter‑long, two‑meter‑wide, vertically oriented, natural, oval‑shaped opening. Like the other caves in the area, the Arany-lyuk is probably of karst origin. According to György Szentes, it is of karst origin and was later modified by cold water and mechanical effects. According to István Szenthe, only karst processes played a role in its formation, because water cannot drain from the surface due to the water‑impermeable clay layer. It begins with a shaft that is formed above in Oligocene, three‑hill limestone and below in Upper Triassic Dachstein limestone.

Branching and multilevel cave. Horn, shaft, spherical niche, spherical chamber, wave shell, fingertip, hanging stalactite, standing stalactite, stalactite rod, stalactite poisoning, stalactite drainage, microtufa, crystalline pea stone and spherical pea stone occur in it. From its discovery it is heavily destroyed and constantly blocked. Most of the cave can be traversed with basic caving equipment, but rope‑technical tools are required for exploration. Permission from the Danube–Ipoly National Park Directorate is required for viewing.

The cave appears in the literature under the names Aranyhegyi Cave (Leél‑Őssy 1958), Arany‑hegyi Cave (Sásdi 2000), Aranyhegyi Cave (Bertalan 1976), Aranylyuk (Révai 1938), Aranylyuk‑zsomboly (Kordos 1970), Kevélyi Aranyluk Cave (Venkovits 1949), Nagykevélyi‑cave (Kordos 1984), Nagy‑kevélyi‑cave (Sásdi 2000) and Nagykevélyi Cave (Bertalan 1976). In 1976 the cave was first called Arany‑lyuk in the literature.

Research History

The 1938 issue 3–4 of Természetbarát mentions that the TTE speleologists planned, if there was enough interest, to lead a cave tour around Pest (e.g. Kevély Cave, Szemlő‑hegyi Cave, Ferenc‑hegyi Cave, Pál‑völgy Cave, Solymári‑ördöglyuk, Legény Cave). Work carried out in the Aranylyuk sinkhole on the Nagy‑Kevély silver‑mountain part had to be abandoned by the association because heavy rain caused a collapse of the middle section of the approximately 70 m cave segment uncovered by the association. The cave had been mapped earlier by association members before the collapse. The association warns that it is currently life‑threatening to descend into Arany‑lyuk.

Between 1941 and 1943 the collapsed entrance was made passable again by István Venkovits, who also carried out entrance enlargement by blasting. István Venkovits probably surveyed the points lost in 1943, based on which he drew a photoreproduced plan cave map. A surveying error caused the direction of the lower passages to be incorrect. In 1951–1953 Sándor Leél-Őssy reached the second class mine, after which the cave became blocked and the lower part became inaccessible. According to the book Pilis útikalauz, which saw daylight in 1955, the dome of the Arany-lyuk is located on the ridge.

The study published in 1958 by Sándor Leél-Őssy mentions that the degradation of the Kevély mountain group and its youthful movements are evidenced, for example, by the high‑lying, dying, dry spring caves as well as water‑origin caves. The Aranylyuk, lying at 400 m above sea level, is such a cave. In the Kevély mountain group there is only one collapsed doline, which is small but typical. This doline is located next to the Arany-lyuk. The water sink next to the Aranylyuk developed at the bottom of the small doline. Around the Aranylyuk (a covered karst formation) a few‑meter‑thick sandstone layer of the Hárshegy covers the surface of the Dachstein limestone. Another name for the Aranylyuk, incorrectly, is Aranyhegyi-barlang. The ridge between Nagy‑Kevély and Ezüst‑hegy at the eastern end of the ENY, at about 400 m above sea level, about 10 m east of the ridge tunnel, in a hard‑to‑find location, formed in dense shrubbery, is where the Aranylyuk was created. The cave formed in covered karst. The cave entrance opens in Hárshegy sandstone, but at about 4 m depth the cave runs in Dachstein limestone.

The cave starts with a vertical shaft of about 4 m, after which, beyond a narrow passage, follows a sloping shaft about 10 m long. The end of this shaft is completely blocked. The outer shaft is most likely a broken stalactite, while the inner part can only be of speleothem origin, but is currently decaying and dry. The speleothem formation is confirmed by many large dome chambers observable in the interior of the cave, which are typical. Apart from the dome chambers, there are no speleothem remnants (e.g., crystals) in the cave. The location of the cave passage was determined by a tectonic fault. István Venkovits penetrated the very narrow and dangerous second constriction at the end of the sloping passage and explored the lower parts of the cave, but this part has become blocked again since then. The speleothem formation of the cave is evidenced by the fact that not far from the cave, on the D side of the Ezüsthegyi ridge, the dolomite surface is heavily dusted. A map sketch is attached to the study, showing the Kevély mountain group. The map sketch shows the geographical location of the Arany Hole. In the drawing and the text the cave is marked with the number 9.