Nagyharsány Crystalcave

The Nagyharsány Crystal Cave is one of Hungary's specially protected caves. It is located in the Danube–Drava National Park. It is the longest and deepest cave of the Villány Mountains. There is another specially protected cave in the mountains, the Beremendi Crystal Cave.

Description

The entrance is closed in the quarry located on the western part of Szársomlyó. It can be visited with the permission of the Danube–Drava National Park Directorate, for research, using electric lighting and wearing clean clothing. The first part, about 100 meters long, up to the Great Hall of the Western Branch, is secured with a climbing rope and can be walked on a stainless‑steel walkway at foot level.

It developed in lower and middle Cretaceous limestone. In its upper zone, spacious passages 10–15 meters high and 20 meters wide with a triangular cross‑section are common. Its lower zone consists of winding, narrower passages. The upper part is characterized by spherical chambers and angular large forms, such as halls bounded by straight lines, while the lower part has only rounded forms. Its formation was significantly determined by tectonics. The cave formed along an east‑west fault line, whereas most of the mountain’s hydrothermal caves formed along north‑south faults. The present appearance of the crystal cave is due to its phreatic origin, as indicated by the spherical chambers and the boxwork networks formed by recrystallized calcite veins. Some signs show that cold‑water karstification also shaped the cave, for example the old, dissolved speleothems and the spherical chambers formed in stalactite flows.

In the Hungarian context its relatively high air temperature of an average 14 °C and, based on certain mineral deposits, it can be assumed that the warm karst water cannot be so deep from its cavities. Among its mineral deposits can be mentioned the straw-drop stalactites reaching 1–1.5 metre in length, whose preservation is also special because of explosions caused by nearby mining activity, the coral calcite, the common calcite, the dripstone calcite, the glass‑ball calcite, the centrally hollow calcite column, whose other name is logomit and which was first discovered in Hungary here as this deposit form, the multi‑generation calcite crust, the full calcite, which sometimes fills its cracks to a thickness of more than one metre, the aragonite crystals (aragonite‑like) and the huntite.

It also occurs in literature under the names Nagyharsányi‑cave (Kraus 1995–1996) and the cave of the Nagyharsányi stone mine level I/1 (Takácsné 2003).

Research history

On 7 April 1994 it was uncovered during stone extraction, as a result of an explosion, and shortly thereafter became known to cave‑protection specialists as well. In 1995 its significance became clear during the second nature‑conservation site survey. The survey was carried out by Takácsné Bolner Katalin and Salamon Gábor, who managed to explore about 120 metres of the passage system and discovered mineral deposits considered a rarity in our country. Even in that year further sections were discovered and its length reached 600 metres, of which 556 metres were mapped based on parallel geodetic surveying. Its vertical extent was 60 metres. A sketch plan of the cave’s surface projection and a length‑section cave map were prepared.

In 1995 Pleistocene mammoth bones were found in it, which were identified by Dénes Jánossy and its entrance was also securely closed. The nature conservation authority immediately tightened its visitation after the cave was explored. From May 14, 1998, according to Ministerial Decree 13/1998. (V. 6.) KTM of the Minister of Environment and Regional Development, within the jurisdiction of the Danube–Drava National Park Directorate, the Nagyharsány Crystal Cave located in the Villány Mountains is visitable with the directorate’s permission. Since 2001 it has been a highly protected cave because of its mineralogical and geological values. From May 17, 2001, according to the Minister of Environment’s Decree 13/2001. (V. 9.) KöM, the Nagyharsány Crystal Cave in the Villány Mountains is a highly protected cave. At the same time the provision 1/1982. (III. 15.) OKTH concerning the determination of the circle of highly protected caves loses effect. In 2002 Katalin Takácsné Bolner and Attila Nyerges surveyed it and a floor plan map with sections was prepared.

According to the cave description in the book *Hungary’s Highly Protected Caves* published in 2003, its length is 600 m, vertical extent 60 m and horizontal extent 130 m. According to the longitudinal list compiled by Csaba Egri and Attila Nyerges in the book, the Nagyharsány Crystal Cave in the Villány Mountains with cave inventory number 4150‑4, about 600 m long in 2002, was the 43rd longest cave in Hungary in 2002. According to the depth list compiled by Csaba Egri and Attila Nyerges in the book, the Nagyharsány Crystal Cave in the Villány Mountains with cave inventory number 4150‑4, 60 m deep in 2002, was the 60th deepest cave in Hungary in 2002.

In 2005 the Hungarian mountain sports and tourist encyclopedia published an independent entry for the cave. According to the entry the Nagyharsány Crystal Cave is located in the Villány Mountains and is a highly protected natural value. Its entrance is at Szársomlyó, in the Nagyharsány stone quarry, at an altitude of 166 m a.s.l. The 600 m long, 130 × 30 m horizontal and 60 m vertical extent cave was formed in chalk limestone by the action of warm waters rising from depth. It was opened in 1994 by mining operations. It is unique in Hungary for the rich mineral assemblage of its passages. The snow‑white, coral‑like calcite deposits covering the large surfaces, the developing and re‑dissolved speleothems, aragonites, and the huntite appearing in the nodules, as well as several occurrences of calcite stalagmites (logomit), can be observed. The closed cave is accessible with a permit, with a walking level installed for the protection of the formations. A protective pillar created within the active mine ensures the cave’s preservation.