Day trip to Predjama Castle and Postojna Cave

Have you ever seen the ‘human fish’ or explored a cave castle? We checked both off our list during our time in one of our favourite countries: Slovenia. Postojna Cave and Predjama Castle are two historic sites not to be missed!

About Postojna

Located on the Pivka River, Postojna is a town in southwestern Slovenia that was once a part of the Holy Roman Empire. Today, it is home to two world famous sites brimming with history: Postojna Cave and Predjama Castle. Their cave systems are where the first research on karst topography took place, which are characterized by eroded limestone structures and underground streams.

Read more: Stay in Hotel Jama at Postojna Cave Park

Getting there

By train: The Vienna-Venice line runs through Postojna, with connections to Zagreb, Rijeka, Salzburg, and Koper.

By car: You can reach Postojna in less than an hour from Ljubljana, Koper, or Trieste. Allow 2 hours for Venice and Zagreb.

By bus: Intercity buses from Ljubljana, Koper, Rijeka and Nova Gorica will take you to the bus station in front of Postojna Cave. Check the current bus schedule for exact connections and times.

Note: Visitors with combined tickets can use the free shuttle transfer between Postojna Cave and Predjama Castle from July to September. 

Postojna Cave and Predjama Castle

Postojna Cave

Coined ‘The Queen of All Caves’, Postojna Cave was first discovered in 1818. It receives 5-7,500 visitors per day, reaching more than 37 million visitors over the past 2 centuries. While visitors can only explore the first 5km, the entire cave system stretches more than 24km.

An electric train transports you along a railway that has been around since 1872 for the first 2km. Continue your visit on foot through paths, tunnels, and bridges that are decorated with stalactites and stalagmites. Postojna Cave is the only underground landscape in the world that can be explored using an electric train!

At the end of the journey you’ll find an aquarium containing the proteus anguinus, also known as the olm or ‘human fish’. This blind creature is the largest cave-dwelling vertebrate in Europe, growing up to 40cm long. Its heart beats twice a minute and it can live up to 100 years old. With a diet consisting of small snails and crabs, the olm can go 10 years without eating.

Note: Please listen to the guide and TURN OFF FLASH PHOTOGRAPHY!! Some people just don’t care- I wish there was a way to fine these scums.

Image courtesy of Postojnska Jama

Image courtesy of Postojnska Jama

Image courtesy of Postojnska Jama

Image courtesy of Postojnska Jama

Image courtesy of Postojnska Jama

Predjama Castle

Located 9km from Postojna Cave is the Predjama Castle. As the largest cave castle in the world according to the Guinness World Records, it has been perched up in the middle of a 123m cliff for more than 800 years. 

Half cave and half castle, Predjam Castle was home to Erazem Lueger, a Robin Hood-like knight in the 15th century. His castle was besieged but through a secret passage Erazem was still able to get fresh food and continue his daring deeds. Erazem’s fate was finally sealed when one of his servants betrayed him, revealing the castle’s only weak spot: Erazem’s washroom. A cannonball struck Erazem while he was on the toilet- what a shitty way to die, eh?

Live the life of Erazem as you walk through his bedroom, dining room, knight room, soldiers’ and servants’ quarters, dungeon, and torture chamber. A self-guided tour can easily be done with the informative audio guide that’s included in your ticket.

Tip: Allow 60-90 minutes to explore Predjama Castle.

Kollecting Koordinates - Postojna Cave and Predjama Castle

Image courtesy of Postojnska Jama

Image courtesy of Postojnska Jama

Useful tips & info

  • Prices vary depending on activities and attractions, check current prices and packages here.
  • You can visit both Postojna Cave and Predjama Castle in one day.
  • Make sure you’re the first group in Postojna Cave; it only gets busier as the day goes by.
  • Wear comfortable shoes and bring layers. It gets chilly inside the caves!
  • I can’t stress this enough- do NOT use flash photography as this damages the caves.
  • For more information and current promos, visit their official website, Facebook, Twitter, and Instagram pages.

Disclaimer: Many thanks to the Slovenia Tourist Board and Postojnska Jama for hosting us. All opinions and experiences are honest and our own- we wouldn’t recommend something if we didn’t love it ourselves!

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Kollecting Koordinates - Postojna Cave and Predjama Castle


  1. August 24, 2017 / 3:43 am

    OMG, this is so my dream trip. Postojna keeps popping up on our radar. We do a lot of caving with our kids and this one is so different from any others. And the castle! Excited to visit next year!

  2. August 25, 2017 / 6:03 pm

    Incredible!!! I love caves, and castle, and boating on lakes underground. This place looks amazing above-ground and below. I am going to pin this so I don’t forget about it because it just zoomed WAY up on my list of places to go!

    P.S. I agree with you about the people who disregard the no flash photography instructions. Idiots. 🙁

  3. August 26, 2017 / 6:06 am

    So excited to finally see the cave. Blind cave fish… So Cool. The electric train looks like a good way to do crowd control. Hopefully, I’ll be going on a cave expedition to Janos Mx in October. There are stories of blind cave fish out there they that we haven’t been run to ground yet. Should be fun to get underground again.

  4. August 27, 2017 / 7:17 pm

    It looks like a really cool spot. I understand about not using flash photography, that drives me crazy and my hubby (who is the photographer in the family) never uses it anyway, but does that mean its impossible to do your own photos? Just curious. If I planned a trip to check it out, I would just want to know if I should leave me camera at the hotel.

  5. August 28, 2017 / 3:56 am

    Wow the inside wasn’t what I imagined it would be! The electric train is a cool way to explore the cave. With the lighting, the stalactites and stalagmites look magnificent!

  6. August 28, 2017 / 1:38 pm

    The cave looks amazing! This is my first time learning about the olm, they are quite creepy looking I gotta say. I hope to visit this part of the world soon!

  7. August 29, 2017 / 1:20 am

    This cave is beautiful! And the olm fish sounds so weird and interesting. The castle is also so unique and picturesque. It’s really cool that you can visit both in one day too!

  8. August 29, 2017 / 3:50 am

    It’s so important to be respectful and preserve the landscape! Your pictures make it look like you escaped to another world 🙂

  9. August 30, 2017 / 7:14 pm

    Wow this is so cool! I’ve seriously been dying to go to Slovenia and Postojna Cave is definitely on my list. The little cave fish are so cool and a little creepy looking haha

  10. Julianne
    September 1, 2017 / 4:50 pm

    Those proteus anguinus are kinda creepy-looking with their tiny “hands” … I see why they are called human fish! And ten years without eating? That’s crazy! But other than that, the caves look incredible, and your pictures are beautiful. The castle is totally gorgeous too. You are making me want to book a flight to Slovenia ASAP!! 🙂

  11. September 4, 2017 / 9:15 am

    What exquisite cave formations! I love caves, and this one is magnificent. Like you, I wish there was a way to find the idiots flashing their cameras and have some Monty-Python like ejector contraption that could fling them into space. I’m fascinated with the half-castle half-cave building of Predjama. I would love to see it!

    • October 3, 2017 / 7:41 pm

      LOL that’d be quite the punishment 😛

  12. November 4, 2017 / 7:52 pm

    Those photos are incredible and l’d love to see that cave in person. I’m so with you on people who use flash photography when they’re not supposed to. They totally ruin it and should be fined. That “human fish” is wild!

  13. November 4, 2017 / 9:29 pm

    What a gorgeous place! That looks like a super fun experience. I agree with fining the flash violators. I don’t understand how some people just don’t care and do their own thing!

  14. November 5, 2017 / 3:13 am

    These attractions are just so amazing that it is hard to believe they are promoted more widely. Mind you, too many tourists would just spoil the experience to a degree. I really enjoyed this post and just love your photos. Can’t wait to visit here one day and the fact that it is situated so well on the train line really makes that quite easy.

    • November 5, 2017 / 4:51 pm

      Thanks Nicole! I hope you’ll make your way there in the next year or two 🙂

  15. Abigail Sinsona
    November 5, 2017 / 7:41 am

    I have read a few blogs about Slovenia but this is the first time I’ve heard of these two sites. The cave castle is really interesting to me. I would love to explore that and I am just in awe at how that was built! The Postojna Cave also looks like fun to explore!

    • November 5, 2017 / 4:49 pm

      I hope you’ll get to visit them one day! Very neat and not overcrowded at all 🙂

  16. Lisa
    November 5, 2017 / 8:37 am

    A cannonball hitting you while on the toilet isn’t a great way to die, but it’s memorable! The caves are incredible, and so cool they have that little train to ride on! The human fish is strange yet intriguing at the same time, a fascinating read!

    • November 5, 2017 / 4:50 pm

      They’re so funky looking eh?! I wonder what other living creatures are down there that we don’t know about

  17. Abhinav Singh
    November 5, 2017 / 11:54 am

    Slovenia is such an offbeat destination easily overshadowed by the big wigs. I hadn’t even heard of Postojna Cave and Predjama Castle despite the huge footfalls it attracts. Proteus anguinus aka the Human fish looks so scary and interesting!

    • November 5, 2017 / 4:49 pm

      Agreed that it’s always overshadowed but its tourism is starting to pick up in recent years.. although I’m not sure if it’s a good thing or not because I kinda like it as a hidden gem haha!

  18. November 5, 2017 / 6:49 pm

    The cave look unrealistic, the landscape so surreal!!! Human fish? That looks so intriguing.. I’ve never heard of it. Gonna read more about it. 24km of this stunning beauty? Hope I’ll get a chance to explore it all!

  19. November 5, 2017 / 8:04 pm

    Now that’s what I call a cave, a little train and everything. It’s nice to see parts of Slovenia other than Ljubljana and Lake Bled (as awesome as they are) highlighted. It’s a tiny country, but it’s got a lot to give!

  20. November 6, 2017 / 8:04 am

    Both the Postojna cave and Predjama castles are beautiful. I’d take love of pictures here(but without photography flash). And the Human Fish???? I would love to see. I’ve been wanting to visit Slovenia but need adequate reasons, now I have one. Thanks for the tips too. It would serve useful.

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