We departed the train inside the hollowed earth and walked in the darkness as our eyes adjusted to the dim lighting. Outside, the Slovenian summer sun was already hot, but 2km deep in the Postojna Cave, the damp air cooled our skin and clung to our clothes. As we stood in the vast space, known as the Great Mountain, we were beginning to see our surroundings more clearly…and we were in awe.
The massive 24km passageway – of which we would walk 1.5km – was formed millions of years ago by the underground Pivka River; the water dissolving the limestone and creating open space below the earth’s surface. In the thousands of years that have passed since the cave was created, nature has been slowly, but steadily, decorating the interior with an array of rock formations. The stalactites and stalagmites created by water dripping through the earth’s crevices are stacked from the floor and dangling from the ceiling like petrified icicles – creating a beautiful, yet surreal, scene.
Visiting Postojna Caves
Although we are not the first or among the few to have seen the inside of Postojna Caves (the cave has been open to the public since 1819 and just welcomed their 37 millionth visitor), we felt like explorers discovering the cavernous corridors. We were guided from the Great Mountain across the Russian Bridge into the Beautiful Caves, so aptly named for the fact that it is, indeed, the most beautiful part of the underground tour.
We walked through three distinct sections, which felt like walking through galleries at an art museum. In the Spaghetti Hall, thousands of thin, white stalactites hang from the top of the cave, which to us looked like a shreds of cheese dangling from a giant cheese grater. In the next gallery, the White Hall, enormous, white stalagmites stand like dripping candles; the rocks’ pearly appearance is obtained from concentrated calcium carbonate. In the Red Hall, the stalactites and stalagmites are rust colored, attributed to the iron minerals from the soil above.
Some stalactites and stalagmites are so unique that they’ve been nicknamed. The “Leaning Tower of Pisa” resembles the building it is named after; “Romeo and Juliet” are two, long, skinny columns that have joined into one; the “Organ” looks like an organ perched in the church choir and “Brilliant” looks like an enormous diamond on display (although, we think it looked more like a double-scoop of ice cream).
Throughout the cave, two other colors appear – black and green. Black is a naturally occurring pigment from manganese, but the green is mold. The unnatural lights introduced to the interior of the cave facilitate the growth, which is why lights are used sparingly and camera flashes are prohibited. To show us the true darkness of the cave, at one point on the tour, our guide extinguished the lights and we were enveloped in complete blackness.
Mold, however, isn’t the only thing living in the cave. There are more than 100 species that call the cave home. Insects and spiders make up the majority of the list, but the most interesting creature to dwell in the cave is the Proteus, also referred to as an Olm, Human Fish and Baby Dragon. The pale pink, salamander-like animal is completely blind, grows to almost 12 inches, lives to be 100 years old and can go without food for 10 years at a time. Since these creatures would be fairly difficult to find naturally within the cave, a large aquarium holding Human Fish is located inside the cave so that we could get an up-close view. Our visit in the summer of 2016 also coincided with a rare event: the birth of baby Proteus. Although they weren’t yet ready to be formally introduced to the public, we could watch their movements on a video screen.
The last ‘room’ on our tour before boarding the train to exit the cave was the Concert Hall. The room holds an echo for five seconds and has been used as a performance hall by various singing groups – and even an in-cave basketball event. Also in the room is the world’s oldest underground post office, which has been post marking parcels since 1899.
Our tour of the interior of Postojna Cave lasted about an hour and a half, but with the “Perfect Experience” ticket, there was more to see. We had access to the on-site, underground zoo and expo center – as well as the nearby Predjama Castle. At the end of our cave tour, it seemed our day was only beginning.
Visiting Vivarium Proteus and Expo Center
The underground zoo, Vivarium Proteus, features the insects and other creatures that inhabit the Postojna Cave. In 1831, the first cave beetle was discovered and it launched a new branch of biology, known as Speleobiology. A small laboratory and display exhibits are located within Vivarium Proteus.
To gain a better understanding of the history of the cave, we visited the expo center. Informative and interesting displays of the creation of the cave, as well as the story of the discovery and promotion of the cave as a tourist sight, were highlighted. Particularly intriguing were the details of how the cave was originally equipped to handle the visitors, including how the cave was lit and the development of the interior railway, which has been in existence since 1872.
Lunch at Proteus Restaurant
The Predjama Castle was the final site we would visit, but the castle is actually about 10km from the cave. Before hopping on one of the free shuttles from the cave to the castle, we detoured 1km from the cave to the town of Postojna for a lunch fit for royalty at Proteus Restaurant.
The bright and atmospheric restaurant serves first class cuisine. Our decadent, two-hour, five-course lunch – of which the highlights were baked octopus in a tomato sauce and glazed lambchops – was complimented with Slovenian wine.
Visiting Predjama Castle
When we arrived at Predjama Castle in mid-afternoon, we leisurely wandered the grounds before entering. An impressive sight, the castle is perched in the middle of a 400-foot cliff. Built 800 years ago during the Middle Ages, the castle was constructed to incorporate a natural cave, which provided secret passageways, a natural water source and hidden rooms.
We moved at our own pace through nearly every room in the castle, utilizing the audio guide that is included with admission. In each room, we were provided a bit of history about how the space was used – from the dungeon to the dining room to the chapel – and even into the interior of the natural cave.
Details for visiting Postojna Cave and Predjama Castle
Official Site: Postojnska Jama
Tickets: Postojnska Jama Ticket Page
Getting There: Directions and Transportation Information
Fortunately, there is a public bus direct from Ljubljana to Postojna Cave operated by Arriva. Search the online schedule from Ljubljana (Ljubljana AP) to Postojna Cave (Postojnska Jama). Cost is €6 each way.
What to Wear:
The temperature inside the caves is about 46-50˚F year-round. I felt silly carrying a fleece jacket with me in the middle of August, but I was happy to have it after entering the cave! They also rent jackets at the cave entrance for those who come unprepared.
Thinking about also visiting Skocjan Caves? Read about our visit to Skocjan Caves here!
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We want to know: Have you visited Postojna Cave and Predjama Castle? What were the highlights for you? What other caves have you visited? Tell us in the comments!
A special thanks to Postojnska Jama for hosting us; as always, the opinions expressed in this post are our own.
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