Topolnița Cave

Topolnița Cave is located at 30 kilometres (19 mi) from Drobeta-Turnu Severin, between the villages of Marga and Cireșu.[9] It has at least four entrances.[6] The cave's primary entrance is in the central part of the Mehedinți Plateau, where the Topolnița River plunges 50 m (160 ft) down into the earth.[2] The river later emerges farther downstream at the foot of a hill.

Topolnița Cave has a huge number of passages and galleries arranged over five floors, many of which have attracted fanciful names as a result of the speleothems that have formed in them.[9] One of the largest galleries, at 1,570 m (5,150 ft) long, is named the Racoviță Gallery in honor of Emil Racoviță, a noted Romanian explorer.[2][12] Approximately 100–150 m (330–490 ft) from the entrance is the Bat's Gallery, containing a bat colony and a large guano heap.[13] Other features within the cave include lakes, waterfalls, rapids, and massive forests of stalactites and stalagmites.[10] Neolithic remains have also been found within the cave.[10]

Best described as "labyrinthine", Topolnița Cave is a difficult cave to explore even for experienced cavers.[14][15] Access for tourists is permitted only once per year, on a feast day in August, where guides lead tours 100 m (330 ft) into the cave to view the Racoviță Gallery.[10][16] Otherwise, the cave is gated and access is only available by permission of the Romanian Academy.[12] In the 1980s, there was some government interest in adding tourist-access features such as stairs, railings, and electric lights, but funding fell through before the Romanian Revolution and nothing was completed.[16]

The cave's temperature hovers between 8.2–10.8 °C (46.8–51.4 °F), making it a relatively warm cave.[9] As a result, it is a suitable habitat for some fauna, including the largest colony of greater horseshoe bats in Europe.[17] A 2015 survey conducted as part of an effort to protect Romania's bats found 7,482 individual horseshoe bats living in the cave.[17] The colony in the Bat's Gallery is mainly composed of insectivorous Mediterranean horseshoe bats, Daubenton's bats, and long-fingered bats.[13] Radiocarbon dating has shown that the bat guano from that colony has been continuously deposited since 1694.[13]

In 2009, a pair of bearded vultures was spotted at the cave by hunters. The sighting was treated with some excitement, as the bearded vulture is no longer extant in Romania.[18]

Plenty of invertebrate species live in or around Topolnița Cave. Specimens of Clausiliidae, or door snails, such as Macedonica marginata, have been found in the cave.[19] A number of species of Opiliones, colloquially known as harvestmen, have been recorded.[20]