Ördögárok utcai Cave

The Ördögárok Street Cave was among the specially protected caves of Hungary. It is located in the Buda Hills within the Danube–Ipoly National Park, in District II of Budapest. It is the longest cave of Fazekas Hill.

Description

In District II of Budapest, specifically on the edge of the Fazekas Hill massif, in the Ördög-árok valley, it opens in front of house number 68 on Ördögárok Street. It is located on the parcel with cadastral number 50012 of Ördögárok Street. It is the longest cave of the hill. The cave is phreatic or of thermal water origin, its presumed formation time may coincide with that of the other Buda karst water caves. The cave can be accessed by opening the specially designed cover of the manhole in the middle of the roadway. Its passages are located near Ördög-árok, extending deep below the stream level. Its length is 45.1 metres, its vertical extent and depth are 21 metres.

According to Szabó Gyula, who prepared the first description of the cave, the cave may have been formed by karst waters breaking along north–south oriented tectonic fractures. The descending part was formed with reinforced‑concrete rings set on a reinforced‑concrete base, built alongside the rain‑water channel. South of the base slab is the first natural cave chamber, from which the main fissure of the cave can be reached a few metres to the west, descending to the bottom of the cave. Parallel to this, a bypass passage also leads to the deeper parts of the cave.

The most characteristic mineral in the cave is calcite, which occurs in various crystal forms. Typical features of the cave are spherical chambers and other karst solution forms.

Some researchers consider it possible that the still unknown sections diverted the water of the Ördög-árok stream into the karst. It was a specially protected cave. It can be visited with the permission of the Danube–Ipoly National Park Directorate and for research purposes.

The cave also occurs in the literature under the name Ördögárok-utcai-barlang (Takácsné 1990). In 1998 the cave was first called Ördögárok utcai-barlang in the literature.

Research history

The cave was discovered when the large-diameter stormwater pipe on Ördögárok street in Hűvösvölgy was being constructed in the summer of 1989. During the work, after a heavy rainstorm, the large amount of stormwater disappeared in a cavity (formed in Dachstein limestone) on the southern part of the work trench in front of property number 68 on Ördögárok street, taking away pipe elements with it.

Research reports on the cave are available from seven years: 1989, 1990 and 1993 by Erzsébet SC, 1995 and 1996 by the Poligon Cave Research Geological Hydrological Association, and 2002 and 2004 by Sándor Kraus, each containing information about the cave. During the first 1989 investigation, geological examination of the cave was also carried out alongside the exploration. The first map of the cave was made using data from the survey conducted on 27 July 1989. The map was edited by József Kárpát with the assistance of Attila Kiss and Katalin Bolner Takácsné. Erzsébet SC had a research permit for the cave in 1990. Exploratory work in the cavity also took place in 1993. The research conducted by the Poligon Cave Research Geological Hydrological Association was carried out for the first time for protection reasons. In 1996 a new section of the cave was explored. At that time a map of the enlarged cave was prepared. The 2002 and 2004 research reports only describe the cave.

The research group led by Gyula Szabó of Erzsébet SC could only determine in 1989 that the passages probably continued in several directions from their then known endpoints, but they were filled with large amounts of clay. In December 1993 the Erzsébet SC researchers attempted to widen one constriction, but were unsuccessful. Szabó Gyula reported in 1995, already as a researcher, that continuous infiltration of surface rainwater into the cave had the disadvantage that a clay‑blocked siphon was washed out in the years since its discovery, and that the previously high carbon‑dioxide‑concentration cave air had become permanently clean.

The condition of the cave did not deteriorate further in 1996, the harmful surface influences decreased, which was reinforced by the regular conservation activities of the cavers. The association’s researchers also concluded that the cave probably continues in the direction of the smaller caves and cave‑like phenomena discovered in the former Fazekas‑hegy stone quarry, a hypothesis supported by reports of minor building movements of houses situated in the presumed continuation directions. In that year the cave’s plan map and longitudinal section map were completed. The maps were edited by Gyula Szabó using data from a cave survey conducted on 27 November 1996 by the Poligon Cave Research Geological Hydrological Association, with lost points. The maps present the cave at a scale of 1:100. The east direction is indicated on the two map sheets.

Since May 14, 1998, according to Ministerial Decree 13/1998. (V. 6.) KTM of the Ministry of Environment and Regional Development, the Ördögárok Street Cave located in the Budai Mountains within the jurisdiction of the Danube–Ipoly National Park Directorate may be visited with the Directorate's permission. In 2002, Sándor Kraus also hypothesized that there is a continuous but narrow passage system in the area. According to the idea, this passage system connects the Ördögárok Street Cave with the other, partly already inaccessible, karst-origin voids of Fazekas Hill. However, in 2004 Sándor Kraus considered it important to emphasize that the connection of the karst-origin passages formed along the Ördög-árok fault line to a cave system is not certain.