Denevéres Cave

The Denevéres Cave is a cave located in the Pilis Mountains within the Danube–Ipoly National Park, in Oszoly, which is also described in tourist guidebooks.

Description

In the outskirts of Csobánka, at the second large rock group located at the foot of the É hill from the Oszoly Óra-fal (Clock Rock), there is a 1.2 m wide, 1 m high, barrel‑shaped entrance. It opens 20 m away and 8 m lower at a bearing of 325° from the Pénzes Cave. The slightly upward‑sloping interior cave consists of two large dome‑shaped chambers connected by a low passage. A broken ridge beginning on the ceiling of the first chamber reaches the surface. In the passage formed in Upper Triassic Dachstein limestone, fossil dripstones are present, and many montmilch can be observed in the inner chamber. In the almost completely untouched cave (true to its name) bats occur. No permission is required to visit the cave, which can be walked through easily without basic caving equipment.

In 1974 the cave was first called Denevéres Cave in the literature. In the literature the cave also appears under the names Denevér‑cave (Nyerges 1996), Denevéres cave (Kordos 1971), O.V. (Kordos 1971) and the 2nd cave from Órafal to É (Kordos 1971).

Research history

In the 1967 book Pilis guidebook it was reported that, on the Ny side facing Oszoly from Csobánka, several insignificant cavities are found among the forest‑surrounded limestone rocks. According to a notice published in the 1969 Karst and Cave Research Bulletin, in August 1969 the Speleology Cave Research Group placed fixed points in the Oszoly and the Oszoly‑side’s eight smaller and larger cavities during a camp organized in Kevélyek. In 1969 Sándor Dunai surveyed the cave with fixed points and a mining compass. Based on the survey, László Kordos edited and drew a 1:100 scale floor plan map with a cross‑section and a longitudinal section map.

In 1969 Ilona Ilona Wehovszky and Ádám Welker surveyed the cave with fixed points and a mining compass. Based on the survey, Ilona Ilona Wehovszky edited, László Kordos drew a 1:100 scale plan map with two cross‑sections and an unfolded longitudinal section map. On 22 March 1970 László Kordos examined the water seeping from the walls. On 10 April 1970 Lászczos Kordos performed a bacteriological examination in the rear chamber of the cave using an agar‑agar plate, a standard Petri dish, and a 10‑minute exposure. After 24 hours of incubation at 25 °C, 64 bacterial and 4 fungal colonies developed. In 1970 László Kordos and Péter Welker examined the cave climate with an Assmann-type aspirating psychrometer.

The 1970 report of the Speleology Cave Exploration Group states that the Denevéres cave is also known as the 2nd cave from Órafal to É and O.V. (Szenthe 1969). The second large rock formation located from the Óra-fal to the É opens at the foot of the É. Its entrance is located about 10 m below the Bone cave and about 8 m above the Rose‑grove passage. The cave consists of two large dome‑shaped chambers. In the main dome of the first chamber a passage formed along a crack leads to the outside. The cave, probably formed by karst water, developed in Upper Triassic white Dachstein limestone. In both chambers the fill is black, clayey‑humus. The 9 m long and 3.5 m deep rear chamber is always wet, the first chamber only during snow melt. The cave can be visited without equipment. In 1969 István Szenthe mentioned that in 1969–1970 the Speleology Cave Exploration Group studied the cave, which locals visit relatively often. The annex of the report includes the maps made in 1969.

In the book Pilis útikalauz published in 1974, in the list of caves of the Pilis Mountains and the Visegrád Mountains (pages 19–20), it is mentioned that among the caves of the Pilis Mountains and the Visegrád Mountains are the Oszoly caves and the Denevéres cave. According to the section describing the caves of the Pilis Mountains, there are about a dozen small caves among the Oszoly rocks rising above Csobánka. These were mapped and regularly explored by the Speleology Cave Exploration Group. Most of these small caves are not very spectacular, but they must be mentioned because some of them provide excellent bivouac possibilities in the rock walls of Oszoly, which are regularly visited by tourists, especially rock climbers, and in their vicinity. In the foothill of the second large rock group rising from the Óra wall to É, at the foot of É, about 10 m below the Csontos cave, the entrance opens to the Denevéres cave, which consists of two large dome chambers and is 9 m long. About 6 m below it there is a connecting cave.

The part of the 1970 report concerning caves was published in the 1975 MKBT Report together with the maps included in the report. In the compilation the name is Denevéres cave. The publication contains a site drawing on which the geographic locations of Csúcs Hill and the Oszoly caves can be seen. The geographic location of Denevéres cave can be observed on the drawing.

In a manuscript written by Bertalan Károly and completed in 1976 it is stated that the Denevéres Cave is located in the Pilis Mountains, in the Kevély group, at Pomáz. Its entrance is at the foot of the second large rock group É, which lies between the Óra wall and É. It is located about 10 m down from the Csontos Cave and about 8 m up from the Rózsalugas passage. The cave, consisting of two large spherical chambers, is 9 m long and 3.5 m deep. At the top of the first spherical chamber there is an opening formed along a crack that leads to the outside. The part of the manuscript concerning the cave was written based on two literary works.