STA, 20 May 2020 - Slovenian speleologists have discovered several new passageways in the cave below the famed Predjama Castle in western Slovenia indicating that the cave, already among Slovenia's longest, is much bigger than thought.
Until last year the cave system was known to be almost 14 kilometres long, but in the last few months nearly 1.6 kilometres of new passageways have been discovered by members of speleological societies from Ajdovščina, Borovnica and Postojna.
Spelunkers have spent three decades exploring possible extensions of the known cave system. The most likely direction was west of the known cave, where several small waterways were known to lead towards the Vipava river.
The exploration was stepped up towards the end of 2019 and by February two new segments with a total length of 154 metres had been discovered.
In early March, two more passageways, one 251 metres long and the other 1,189 metres, were discovered before exploration was suspended due to the coronavirus epidemic.
The 1,189-metre passageway, named after the recently deceased speleologist Marjan Vilhar, had been carved out by an underground river millions of years ago before it retreated to deeper reaches of the cave.
Multiple smaller tunnels jut out from the main passageway and they are yet to be fully explored. One of them comes to within a few dozen metres of a known smaller cave. If they are found to be connected, the confirmed length of Predjama Cave would increase by almost a kilometre.
Predjama Cave is among the top five longest caves in Slovenia. It is also the second longest show cave behind Postojna Cave.