Széchy Dénes Cave

Széchy Dénes Cave is one of the specially protected caves of Hungary. It is located in the Visegrád Mountains in the Danube–Ipoly National Park. Archaeological finds have been recovered from it.

Description

The most significant cave of Várhegy in Esztergom. The cave is located on the north‑eastern, steep side of Várhegy, in a built‑up surface, and has two artificially created, rectangular, horizontally oriented entrances. The lower, right‑hand entrance, which is 1.8 m high and 0.9 m wide, is at the foot of a rock wall, while the upper, left‑hand entrance, which is 1.8 m high and 1 m wide, is in the middle of the rock wall. From the lower entrance of Széchy Dénes Cave to point D, within 20 m, is the built‑up cavity of Esztergom Várhegy. Széchy Dénes Cave is situated between the second numbered cave of Esztergom Várhegy and, lower down, the third numbered cave of Esztergom Várhegy.

The cave formed in Triassic Dachstein limestone and Oligocene Hárshegy sandstone along a stratigraphic boundary due to rising warm‑ish karst water and collapse. In the cave a breccia zone is observable (on the upper level of the limestone in several places, on different planes), barite ore (local occurrence), limonite (widespread, in several forms, as a vein, the cement of the breccia), overgrown barite (in traces, isolated, 1–1.5 cm), massive fine‑crystalline (alabaster) gypsum (crust, widespread, only on walls, 1–15 mm thick) and fibrous‑needle gypsum formations (flower, in some places massive). A boxwork structure, formed from limonite cementing the limestone, characterises the majority of the cave.

In Esztergom's Víziváros district, between houses numbers 11 and 13 on Berényi Zsigmond Street, one must ascend the steep staircase leading to the Basilica (Macskalépcső) above the level of the houses and gardens. Here, on the right side, the sandstone excavation supporting the walls of the old palace can be seen, as well as the masonry and concrete support. In the stone wall two iron‑grated openings are observable, which close off the Széchy Dénes cave. One can climb the low, steep slope to the lower situated entrance, under whose grate one can crawl into the cave.

The dusty floor of the Entrance chamber contains some trash, indicating that the cave is occasionally used. The ceiling and the right‑hand (D‑side) wall are largely gray sandstone, the remaining surfaces are cracked Triassic limestone, colored bluish and brown by leaching iron compounds. Opposite, through a passage, one can go into the First chamber, where it feels noticeably warmer in cool weather. Its ceiling is also sandstone, which is wavy due to layer detachments. At the contact between the main limestone and the side limestone walls a 1–3 cm thick limonite crust can be observed, whose material also penetrates the limestone cracks. The floor here is not dusty, but not wet. To the right a small pit is visible, but one must continue straight ahead. Where the floor begins to slope down, on the left a very eroded, continuous gypsum crust shines on a sloping surface. From there further on, most of the ceiling is covered by gypsum crust colored brown.

It is possible to descend a small shaft into the Lower Chamber, which slopes to the left and is closed with loose material. There is also gypsum crust on the ceiling here. To the right (DNy) a trashy pasture area is reached by walking back. The small shaft that opens in the First Chamber also leads here (this part is incorrectly shown on the map). On the wall of the passage branch that goes to the left (K) there is white, continuous gypsum crust 1–2 cm thick. Barite plates protrude from it, measuring 5–15 mm. The floor, covered with stone rubble and loose sediment, is dirty, with limestone spots making it uneven. The material of this very fissured, ancient karst surface is cracked and crumbly. It was covered by Miocene coastal sand, in which scattered pebbles occur.

Emerging from the small shaft into the First Chamber, then climbing up along the outer stone wall from the Entrance Chamber, one can reach the Large Chamber located on the E side, which is large in size as its name suggests. The ceiling is brown and gray sandstone, and its base is composed of purple, very fissured limestone. On the sandstone surfaces, especially at the stratifications, thin gypsum crusts with brownish and yellowish discoloration are visible in many places. The crust detaches in flakes from larger surfaces. On the inner side of the chamber, on a floor covered with purplish‑red dust, a short side branch can be looked into, where gypsum crust is also found. To exit, one must go down along the stone wall back to the Entrance Chamber. Apart from the archaeological material found in it, the cave is significant because of the extensive, but damaged, dirty gypsum crust covering the large surfaces. In addition to studying the contact surface of limestone and sandstone, the old ancient karst surface is also of interest. The sealed cave can be visited with permission, using basic caving equipment.

In 1988 the cave was first called Széchy Dénes Cave in the literature. The cavity was named after Széchy Dénes, the archbishop of Esztergom. The cave appears in the literature under the names Basilica cavities (Kadić 1952), Basilica cavities (Bertalan 1976), Esztergom Basilica Hill cavities (Bertalan 1976), Esztergom Basilica Hill cavities (Schőnviszky 1937), Esztergom Basilica‑Hill cavities (Bertalan, Schőnviszky 1976) and Széchy Cave (Eszterhás 2014).

Research history

The 1926–1927 Cave Research mentions that during bat observations carried out in 1923–1924 by András Tasnádi Kubacska and Lajos Véghelyi, on 20 February 1924 a male brown long‑eared bat (Plecotus auritus L.) was found in one of the five smaller‑larger cavities and caves located in the Mesozoic limestone of Vár Hill in Esztergom. In the 1937 issue of Turisták Lapja, in a study written by László Schőnviszky, it is mentioned that the Esztergom Basilica Hill cavities are located in the Mesozoic hill rock scree. Five smaller‑larger cavities, which are insignificant. In Ottó Kadić’s manuscript completed in 1952, the Basilica cavities (Esztergom) are mentioned using László Schőnviszky’s 1937 publication. In Esztergom, in that limestone scree on which the basilica was built, a few smaller‑larger cavities have formed. These have not been investigated by anyone so far.