In the historical region of Inner Carniola in the South-Central part of Slovenia is located the village of Predjama. Postojna Caves is about 10km from here.
Predjama is a quiet, idyllic village which gained prominence because of Predjama Castle which is a picturesque castle perched on a 123m high cliff.
With more than 700 years history, Predjama Castle was built in 1274 by the Patriarch of Aquileia in Gothic style. It was later acquired and expanded by the Luegg noble family, known also as the Knights of Adelsberg (German name of Postojna).
This castle sitting on a natural rocky arch was virtually impregnable and thus became the perfect hideout for the bold and defiant ‘Robber Baron’ Knight Erazem Lueger during the 15th century. Within the castle lies Erazem Tunnel is a secret passageway that rises vertically and reaches the top of the cliff some 25m away from the cliff’s edge.
The castle is pressed next to the vertical cliff under the original Medieval fortifications and was rebuilt in 1570 in Renaissance architectural style when it was leased out to Baron Philipp von Cobenzi. It has largely remained unchanged except in ownership. From 1846 till the end of WWII in 1945, it belonged to the Windischgratz family until it was nationalized and turned into a museum by the Yugoslav Communist State.
We boarded this miniature double track railway with 140 years history that runs about 3.7km into Postojna Cave or Postojnska Jama in Slovene. In early 19th century, visits to the cave were made on foot but by 1872 the first single tracks were laid and it enabled the transportation of little two-seater carriages which were pushed by the cave guides.
Overwhelmed by the visitor numbers, the system was later renovated in 1925 with locomotives running on petrol being used. The exhaust fumes from these trains reduced visibility and caused a bottleneck when running simultaneously to ferry increasing number of visitors.
Finally on 20th June 1964, a two-track line with a loop near the entrance of the cave and a terminus at the end of the line at the foot of the Great Mountain known as Calvary station was opened.
The second stage was completed in 1968 with the construction of the loop to the Concert Hall where we hopped onto the electric train to exit Postojna Caves. This system provided an efficient, pollution-free and uninterrupted transportation for large number of visitors.
The cave was first discovered in the 17th century by the pioneer of Karst phenomena study, Johann Weikhard von Valvasor. A new area of the cave was discovered accidentally in 1818 by a local Luka Cec, when preparations were being made for the visit of the first Emperor of Austria-Hungary Francis I.
This Karst Cave formation is the 2nd longest in Slovenia making it one of the top tourism sites. Stretching over 24km, it is a unique experience of the subterranean world. We got to see part of this scenic underground maze from the train and enjoyed the second part on foot.
It is quite a steep climb up the Great Mountain but with railings installed by the sides, it is quite safe. The ‘Great Mountain Hall’ was formed when parts of the ceiling collapsed as evidenced by water seepage through the cracks and the calcite deposits of newer stalactites on the ceiling. On the descent from Great Mountain Hall we see the Russian Bridge which links the ‘Beautiful Caves’ section to the artificial tunnel, the ‘Russian Passage’. Visitors can pass through to the other parts of Postojna Caves without back-tracking.
This reddish coloured flowstone which is interestingly shaped like a tulip got its colouring from admixtures of iron and clay that was found in the surface rock above the cave that was deposited together with the calcite in the water that got into the cave.
These delicate Calcite curtains that look so fluid, hang draping from the ceiling in a breathtaking display. The guide explained that it takes about a 100 years for a 1cm growth in the speleothems. Though it is dimly lit within, electricity was added to the caves in 1884 preceding even the city of Ljubljana. The caves maintain a cool temperature of between 8°C to 10°C all year round, so a jacket would come in handy.
We were advised to use no flash photography as the artificial light encourages the growth of moss and lichen on the speleothems and also not to touch any surfaces out of curiosity with our bare hands as the natural body oils deposited on the cavern rocks create a coating that prevents further growth.
The ‘Hall of Tubes’ is where white, needle thin transparent tubes hang from the ceiling and that is why it is also known as ‘Spaghetti Hall’. This is the first hall which forms part of the ‘Beautiful Caves’ and ‘Russian Passage’.
Geologists have analyzed the speleothem damage in Postojna Caves and deduce it was from the movement of melting glacial cave ice. It is highly probable that all or parts of Postojna Caves was filled with ice during the Last and earlier Glacials.
The karst formations in Postojna Caves is indeed very diverse in terms of colour, shape and size. In this section, it looks like a room full of people. Stretch your imagination a little and you will see representations of animals and things.
As we passed this section, the cave guide cautioned us, “Be careful! Don’t knock down this column, the cave walls is supported by this one spindly column.” It was a lighthearted moment and we all broke out in laughter as our guide had earlier kept a straight face and sounded really serious.
Here we see the ‘Twin Towers’ standing tall and magnificently. Walking a little further we were asked if we would like to experience complete darkness before our guide turned off the lights momentarily. It was pitch black and really scary which leaves me amazed at how the Olm aka “human fish”, an albino-like cave salamander can survive under such conditions. We had to peer closely and use our torches to spot them hiding amongst the rocks and plants in the aquarium.
As we entered this section named the ‘Brilliant Passage’, we come in full view of the 5m tall stalagmite ‘Brilliant’ which is a shiny, pure white, unblemished and famous symbol of Postojna Caves and the Gothic pillar beside it. A strong and consistent drip from the ceiling deposits a thin layer of pure calcite sinter trickling down the crown of the stalagmite making it so white and shiny.
On the third leg of our visit we exited via the trains near the ‘Concert Hall’ (the largest cave in all of Postojna Caves) back to entrance. With exceptional acoustics and a seating capacity for 10,000 people, this cavernous ‘Concert Hall’ is the venue of symphony orchestras, octets and a special live Nativity Scene, the ‘Christmas Crib’ to be staged from 25th to 30th Dec 2015.
This tour covers about 5km of the caves and took about 2 hours. It left me marvelling at how nature coaxed these incredible formations into being over millions of years. I was a little skeptical at first, having been to many different caves systems which were fairly interesting but Postojna Caves is not just another cave as it is a fascinating place with something for everyone to enjoy. Visit the Vivarium Proteus which has a research laboratory and an exhibition section to learn about the ‘Olm or Proteus anguinus’ and the 150 animal species that dwell in the caves. A boon is the electric train that takes you into the caves and catching a glimpse of the Pivka River that has been carving the cave for over 2 million years at the lower levels of the subterranean tunnels. A must do on your checklist to Slovenia!