Fazekas-hegyi Felső Cave

The Fazekas-hegy Upper Cave is one of the caves located on Fazekas Hill in the Danube–Ipoly National Park, in District II of Budapest.

Description

The cave entrance is in a former, now non‑operational stone mine dug into the north‑eastern side of Fazekas Hill in District II of Budapest. It is easily reachable by car from the stone quarry, because Torda Street ends almost at the quarry. The Fazekas-hegy Upper Cave has a fissure‑shaped, natural, horizontal axis entrance, 2.5 m wide and 3.4 m high, located in the rock wall of the eastern part of the stone mine, lying 5–6 m above ground. The cave entrance in the Buda Landscape Protection Area is the only entrance in the quarry that is visible from a distance, because it is not hidden by vegetation. No great skill or advanced rock‑climbing ability is required for the few‑meter climb to the cave. Under the Fazekas-hegy Upper Cave, at the foot of the rock wall, is the Fazekas‑hegy Cave. Both caves lie along a distinct fault line and could be joined together.

The Fazekas-hegy Upper Cave, formed in Upper Triassic Dachstein limestone, is 17 m long, 5.5 m high, 0 m deep, with a vertical extent of 5.5 m and a horizontal extent of 9.8 m. The cavity was created by dissolution, corrosion and collapse below the karst water level. It is a stepwise rising, fissure‑type cavity containing many large collapse blocks. These blocks contribute both to the ceiling structure and to the floor formation. (The largest part of the ceiling of the underlying Fazekas‑hegy Cave also consists of collapse material, therefore a connection between them is presumed.) Apart from the smaller and larger rock blocks and rock debris, the characteristic fill is dry, crumbly, clayey material. When visiting the cave, one must move carefully because of the risk of collapse.

In the cave there are few formations, only a small amount of indistinct pea‑sized bark on the front part, but this is powdery, dry and colourless. In the interior of the cave smooth, nicely polished‑worn, wavy stone‑tongue‑like speleothem forms (pendant?) and small spherical‑ear‑shaped dissolution forms can be seen. On the surface of these dissolution forms the cross‑sections of shells of calcite‑shelled organisms (clams, snails) embedded in the host rock are clearly visible. At the entrance part of the cave the structure of platform carbonate sediment is strikingly displayed: in its prepared state the development of the Lofer cycle algal‑tape can be studied. The floor of the fissure‑shaped cave rises, its stepped and characteristic cross‑section type is the fissure cross‑section. The cave, which can be viewed without a permit, is easily reachable by a short walk and is easily walkable. Some rock‑climbing knowledge is required to reach the cave entrance.

Research history

In the 1963 Karst and Cave Research Bulletin, in the report of the BEAC Cave Research Group on its 1962 work, it is written that in 1962 the group members found water‑bearing traces in the tectonic fissure of the Dachstein limestone located in the quarry on Fazekas Hill (Hűvösvölgy), facing Torda Street. According to geological maps, there is freshwater limestone in the vicinity. From the presence of the sheet‑like calcite in the fissure and the freshwater limestone discoverable nearby, the group members inferred the existence of a water‑bearing cave. From the fissure they were able to explore about 10 m diagonally downwards from the fissure entrance. Water‑bearing traces appeared at the end of the fissure, where they proceeded a few metres further between the collapse blocks. The work on Fazekas Hill was halted because it was life‑threatening. The work can only be continued if appropriate equipment is available.

The 1964 Karst and Cave Investigation Bulletin states that on Fazekas Hill in Budapest's District II there is a quarry facing Torda Street. In the quarry, the Dachstein limestone has a small stone niche in its tectonically pre‑formed fissures, which local residents use as a cellar. The BEAC Nature Hiking Section Cave Investigation Group began exploratory work in the stone mine in 1962, opening a water‑origin cavity system. The group members continued the work on Fazekas Hill in 1963. In about 360 hours they removed 10 m³ of rubble and thus advanced about 10 m. A minor accident occurred during the work. Because of the accident the work could have been continued only with insurance, but since they lacked the financial means for this, they temporarily finished the work. They began the geological and mineralogical processing of the site, the precise surveying, leveling and mapping of the area. The map‑making work will most likely be completed in the spring.

The 1964 book titled Geological Excursions Around Budapest mentions that in the large quarry on Fazekas Hill at the intersection of Uzsoki Street and Tordai Street the water’s strong corrosive action can be observed. The fissures, cracks and even larger cavities in the stone mine, some of which are a few meters deep, walkable in size and generally ending in a dome, indicate that the cracks formed by crustal movements have been widened by the dissolving effect of surface water.

There are fissures, cavities, caves in the old large limestone mine’s eastern wall. These show the water’s corrosive work in those places where deeper crustal movement previously occurred. Above house number 7 Uzsoki Street, three larger cavities draw attention. Among them the one leading to the DNy is traversable. On the quarry’s western rock wall a stalactite cluster can be seen, above which a water intake entrance about 5 m high and 0.6–0.8 m wide is located. Here and in the nearby places it would be worthwhile to carefully excavate to verify whether larger cavities, possibly a cave, exist. The abundant cave‑like clay debris blocks the way.