Szurdok-völgyi Felső Cave

The Szurdok-völgyi Felső Cave is one of the caves located in the Pilis Mountains within the Danube–Ipoly National Park.

Description

The cave entrance is on the edge of a ravine, on the steep forested slope of the lower part of the Pilisszentkereszti ravine, at an altitude of 312 m a.s.l. It is a natural entrance, 1.2 m high, 0.8 m wide, triangular in shape and oriented along the slope, situated about 60 m above the stream on the right side of the stream, in a rocky and bushy steep section. In front of the entrance there is a small stone pile, and at the bottom of the cave a pit testifies that trial drilling has already been carried out in the cave. Not far away, on the same side of the ravine, is the entrance of the Szurdok-völgyi water sink.

In Triassic Dachstein limestone the currently inactive cave, 8 m long and 3.8 m deep, was formed by dissolution below the karst water level. The small rock cavity essentially consists of a sloping chamber heavily filled with humus-rich rock debris, which may have been a blocked shaft similar to the Szurdok-völgyi water sink. Opposite the entrance the walls are very mossy and algal even in the inner parts. In the rock‑cave‑type passage the slope conditions vary. The typical cross‑section type is the irregular dissolved section.

At the right‑hand flat widening there are stalactite encrustations, condensation calcite and montmilch. The cave also contains a stalagmite and a stalactite column. The mineral formations are practically untouched. The deepened floor is covered by fallen leaf litter and plant debris, and the walls are periodically moist. Its fauna consists of soft‑bodied animals, spiders, insects, and also small mammals and bat bones occur in it. With a lamp the cave, threatened by infilling, can be easily viewed.

Research history

It was published in the 1948 Hydrological Gazette that with the emergence of Hosszú-hegy the karst water level descended in Hosszú-hegy and the operation of the Ziribári, Hosszúhegyi, Pilisszántói and Szurdokvölgyi cave spring series ceased. Water‑sink caves began to operate in their place, for example the now‑blocked cave located at the bottom of the Szurdok valley, which channels surface water flow deep underground.

The 1953 Geographical Bulletin mentions that on the steep rock walls of the Szurdok Valley, besides the Szurdokvölgyi cave, there are several rock niches. It is possible that these are openings of smaller destroyed caves. The openings are mostly at a greater height, 30–40 m. At lower heights they no longer occur, because the numerous rockfalls and rock slides, which also made the slope gentler, have buried the presumed openings.

In the manuscript written by Bertalan Károly and completed in 1976 it is stated that the Szurdokvölgyi rock niches are located in the Pilis Mountains, in the Pilis range, at Pilisszentkereszt. In the steep rock walls of the Szurdok Valley they open mainly at a relative height of 30–40 m. Smaller passages in the rock wall. Slope debris has buried any possible passages opening at lower levels. The part of the manuscript describing the cave was written based on publication 1.

In the national cave list of the book *Caves of Hungary*, published in 1984, among the caves of the Pilis Mountains, the Szurdokvölgyi rock niches are listed in addition to the Szurdokvölgyi water sink. Related to the list, a 1:500 000 scale map showing the geographical location of the caves of the Dunazug Mountains displays the geographical position of the rock niches. In 2008 Richárd Kovács surveyed the cave and, based on the survey, on 10 May 2008 prepared a plan map with a cross‑section and a longitudinal section map. The cave at Csobánka, with the cave cadastral number 4830‑13, according to the survey is 8 m long and 3.8 m deep.

The cave's registration sheet from 2008 states that the Szurdok-völgyi Felső Cave, with the cave cadastral number 4830-13, is located in Pest County, Csobánka. Its entrance opens at an altitude of 312 m a.s.l. The cave is 8 m long, 3.8 m deep, 0 m high, with a vertical extent of 3.8 m and a horizontal extent of 5 m. A site plan is found in Adrienn Szokol's 2011 manuscript, showing the geographic location of the caves in the cadastral area 4830. The cave's geographic location is marked on the diagram. The Szurdok-völgyi Felső Cave opens in the Szurdok Valley at an altitude of 312 m a.s.l. In the 8 m long and 3.8 m vertically extensive cave, stalactites, montmilch and pepperstone are present.