Kőkapu (Budapest)

Kőkapu is a passage cave located in the Buda Hills of the Danube–Ipoly National Park, in Budapest District II. It is situated near the top of the Apáthy rock on Látó Hill. It was among the specially protected caves of Hungary.

Description

It is located not far from the top of the Apáthy rock, next to a tourist trail marked with a green stripe that runs above the rock. At the base of the very stratified dolomite rocks, behind a debris‑catching log line, a steep path a few metres long leads up to the cave. Dark‑red brain‑like deposits form its floor. Through a window on the left side of the cave one can look out. The upper part of the slope begins in the forest. Here also a log line reduces the inflow of debris.

The almost parallel tectonic planes can be well observed on the ceiling, along which sub‑pendant forms are bounded by frost‑induced fragmentation. The ceiling has a boxwork pattern, which formed during dolomite dissolution. On the entrance side, the surface of the rising main chamber is more uniform, yellowish, which is probably Eocene material. The walls of the cavity are reddish‑brown, possibly due to red clay. No clear limestone material can be identified. The fibrous surface of calcium‑carbonate sponge known from surrounding caves is visible in several spots. Dolomite grain fragments are also cemented in some places. To the left (east) under the upper entrance one can crawl into a small side branch, but it is not worthwhile. The walls and ceiling are very stratified everywhere due to frost fragmentation. No solutional forms are recognizable. The cavity has only geological significance and is speleologically insignificant.

In 1957 the cave was first called Kőkapu in its literature. The cave appears in its literature under the names Apáthy-szikla I. stone gate (Bertalan 1976), Apáthy-szikla 1. stone gate (Kordos 1984), Apáthy-szikla stone gate (Bertalan, Schőnviszky 1976), Lipótmezei rocks cavity (Kordos 1984), Lipótmezei rocks cavity (Bertalan 1976), Szelelő-hole (Leél-Őssy 1995), Stone gate (Leél-Őssy 1995), Iron gate (Bertalan 1976) and iron gate (Kordos 1984).

Research history

In the book titled Budapest surroundings published in 1900 it is mentioned that among the interesting rocks of Lipótmező a large stone gate can be seen, leading into a corridor-like rock cavity. The guidebook published in 1957 describes that by going down to the Kőkapu rock group and carefully climbing up to the right (there is a large stone quarry below) one can reach the Kőkapu, through whose natural and low stone gate one can ascend to the top of the rock group, where the viewpoint-like rock of the rock series is located. According to the study written by Leél-Őssy Sándor that appeared in the 1957 Geographical Bulletin, the cavities of Apáthy-szikla were formed in dolomite and are of karst origin. The location map in the publication marks the position of the cavities.

The 1958 publication titled *Budapest natural scenery* states that in the upper part of the limestone floor, in the stratum assignable to *Triassic* *Trachyceras aonoides*, the white and gray‑white dolomite occurring in the Ápáthy rock is found, which does not contain gypsum, but is just as massive and fractured as the other dolomite. This outcrop (determined from maps) is at the end of the Kőkapu DNy. The cave openings and old tufa‑formation deposits on the side of the Ápáthy rock are 70–80 m above the alluvium of the Ördög‑árok. The caves of the Ápáthy rock are located on the upper part of the dolomite wall facing the ÉNy and include partly artificial small cavities.

The 1959 book *Geography of the Natural Environment of Budapest* mentions that from the rocky slope of Látó Hill down to the DNy, the flat ridge along Törökvész Road separates the small dolomite outcrop of Kőkapu. The valley of Szalonka Road separates Kőkapu towards the ÉK from the Vadaskert mountain group. In addition to the more important and interesting caves in Buda described in the book, there are several dozen small, insignificant cavities in the Buda Hills. Among these, the likely tufa‑origin caves are the János‑hegy passage, the Kecske‑Hill and Upper‑Kecske‑Hill in Óbuda, the cavities of the large quarry on Mátyás Hill, the smaller cavities in the Csiki Hills (Odvas Hill, Kecske Hill), the cavities of the Ápáthy rock and the Máriaremete quarry, as well as the Hosszúerdő Hill cave. Some of these are partly artificial.

The 1966 guidebook to the Buda Hills states that proceeding on the tourist trail from Apáthy Rock, where the ground becomes reddish, one can soon reach under the Stone Gate. One can climb a steep slope to the natural rock gate of the Stone Gate, where the view is picturesque through the low opening. To the right above the gate there is a narrow footpath. In the Hungarian speleological bibliography compiled by Bertalan Károly and László Schőnviszky and published in 1976, the cave in the Buda Hills is mentioned under the name Apáthy Rock–Stone Gate with the variant name Iron Gate. The cave name index lists three literary works that deal with the cave.

The manuscript titled *Hungary’s Cave Register*, completed in 1976, states that the cave named Apáthy Rock I. rock gate is located in the Buda Hills, Hűvösvölgy, District II of Budapest. Its other names are Stone Gate, Lipótmezei rock cavity and Iron Gate. It is situated 150 m from the 257.6 HP to the EK, in a forested‑boggy area. The few‑meter‑long and several‑meter‑high, spacious rock fissure is a ruin of a destroyed cave. It is a freely visitable tourist attraction. Its filling is worth protecting, because archaeological and paleontological finds may be present. The part of the manuscript concerning the cave was written based on seven literary works.