Krizna jama - exploring underground lakes at Cross cave in Slovenia

Krizna jama - exploring underground lakes at Cross cave in Slovenia

Križna jama, also known as Cross cave, is a more than 8 kilometres long cave system in Slovenia featuring a chain of underground lakes. It is considered to be one of the most beautiful and best preserved caves in the world, as well as the fourth most eco-divers system in the world. We were lucky enough to secure a spot on a tour that is only available to a 1000 people per year and were very excited to see for ourselves if the cave is indeed one of the most beautiful ones in the world.

Krizna Jama exploring underground lakes Slovenia

Preparing to go in

As we’re driving past the surrounding hills and mountains towards Križna jama in the morning, one mountain covered in mist especially stands out. It is called Mount Slivnica and legend says that witches live on the top and that when the top is covered in mist it means that they are brewing their potions in their big kettles above the fire.

We hurry onwards to the cave entrance where our tour guide and another couple that is joining us on the tour have just arrived. As the guide hands us gumboots, overalls and a helmet with a torch he tells us to wear at least two pairs of socks and suggests three layers of clothing as the temperature in the cave is a brisk 8°C all year round. He also urges us to go to the toilet while we still can because the tour takes us 3,5 kilometres deep into the cave and takes four hours. After a short safety briefing the five of us head into the cave.


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Into the darkness

Once you enter the cave you step into a large hall with a path leading down the middle. Our guide tells us that the ceiling is about 15 meters high and that this is the 3rd biggest hall in the cave. Once we reach the other end of the cave we stop and notice that dozens of charcoal writings are visible on the wall. The guide explains that these are all signatures of explorers that went into the cave many years ago, some even dating back to the 1600’s, way before the first documented discovery of the cave. As we go around the corner into the next corridor our guide asks us to turn off our torches and we’re suddenly in complete darkness. Only when we look back we can still see a faint glow coming from the entrance.

Meeting the previous occupants

In this next corridor stands a glass box next to the path. When the tour guide flicks on a light it reveals a massive skull inside the glass box. We are told that this is the skull of one of the many cave bears that called this cave home between 45.000 and 145.000 years ago, and that this specimen was only considered to be of medium size… They have found bones in the cave suggesting that cave bears reached sizes four times the size of a grizzly bear. We start hoping, fr our own sake, there’s really none left hiding in the depths of the cave!

Krizna Jama paddling underground lakes Cross Cave Slovenia

Going for a paddle

After our acquintaince with the once furry giant we reach the first underground lake where we get into an inflatable boat. While the guide paddles us across the first lake he tells us about how the stalactites, stalacmites and other rock formations in the cave were formed and that it takes these formations about 10 years to grow a single millimeter. When we reach the shore on the other end we can hear the water siphoning through under our feet. Theres another lake just around the corner and a smaller boat waiting for us. This is where the exclusive part of the tour begins and where the cave starts to show it’s true charm.

Deeper underground

As soon as we pass underneath a low passage we are greeted by countless stalactites in all shapes and sizes hanging over a stream of water that slowly cascades down over the rocks. Then we enter the next lake which is also the deepest lake in the cave. But even though the bottom of the lake lies more than 6 meters below us, the water is so clear that is looks like we can just step out of the boat onto the bottom of the lake.

In the next part we paddle past a rock formation that looks a lot like a pirate ship, which we’re unfortunately enough not allowed to board. Then our way over the water gets split in two by an underground island and we’re told that this 10 by 10 meter rocky piece of land is officially the 11th (Or is it 13th? Should have taken notes!) biggest island in Slovenia.

Krizna Jama Calvary Hall

Alone in the dark

After almost an hour and a half of moving in and out of the boat and going from lake to lake we reach Calvary Hall, in which lies the 13th and final lake of the tour. With massive stalactis connecting to stalacmites and forming crazy impressive rock formtions this is possibly the most impressive scene we’ve seen in the whole cave.

When we’re in the middle of the lake our guide stops paddling and asks us to turn of our helmet torches. Suddenly it is pitch black and all we can hear is the sound of the water cabbling over the rocks and the following thought pops in; “I have to pee!” Then, while suppressing that thought, another thought enters the mind; “Here we are, all alone floating in a little boat kilometres deep into a cave underground, enclosed by total darkness.” Just as it starts to get a bit eerie, the guide pops his light on again and all these thoughts melt away.

After showing us some of the organisms that live in the water and allowing us to take some pictures our guide turns the boat around and we return the same way we came, amazed by the beauty of the cave but rushing to the toilet and to warm up in the sun as soon as we get out.

Want your own unique caving experience?

Krizna Jama offers 4 types of tours into the cave. So which tour should you pick? Well, this will depend on several factors: how much time you have, how much you are into caving, and of course on availability - some tours need to be booed months in advance!

Look, more pinnable graphics!

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1. Visit with boat ride on First lake  (1-1.5h)

The most popular tour is the 1-1.5 hour tour that shows the first 700 meters of the cave and takes you on the first big lake. This tour does not require reserving upfront.

If you never visited a cave, the short tour will be enough to get the feeling for the underground world. You’ll go for short a boat ride on the first lake underground and see the cave bear skull, however this part of the cave doesn’t offer many cave formations. If you want to see some impressive underground scenery, but don’t have time to do a longer tour, we suggest you visit the more commercial Postonjska or Skocjanska jama.

2. Visit with boat ride on First lake and Bear tunnel (1.5-2h)

The alternative tour takes about 2 hours and adds the Bear tunnel to the tour which is, as the name suggests, where they’ve found large quantities of bear bones.

This tour takes you into the Bear tunnel where the cave bears used to hibernate over winter. You’ll also see the small Tiberian lake. We haven’t done this part of the tour so we can’t give any first hand advice on it, but it sounds like the perfect options for anyone interested in learning more about this prehistoric species.

3. Guided tour to Calvary (3.5-4h)

This is the tour that we did and it takes 4 hours. Since the tour is limited to 1000 people per year you need to book it well in advance. This tour takes you over 13 lakes, shows you some impressive cave formations and ends with a little stroll around Calvary hall before returning back the same way.

We absolutely loved this tour, the cave is stunning and being able to float around on a little boat makes it so much more magical. It really is a unique experience! We feel like this tour has the perfect balance between scenery and length, the 4 hours passed in a heartbeat. If you opt for this tour (and you should!) make sure to listen to the guide’s suggestions and wear that extra pair of socks and a layer on top. While 8°C might not sound too extreme, the humidity is very high and you will get cold after several hours sitting in the boat.

4. Guided tour to Crystal mountain (6.5-7h)

And finally, the longest one that shows you the full 8 kilometres of the cave and takes you to the biggest hall, all the way to Crystal mountain. This tour takes 7 hours and is limited to 100 people per year.

This one is for true cave lovers. While we’re sure it’s well worth the time and shows you some stunning underground scenery, we felt this tour would be too long for us. We were freezing and ready to pee our pants after only 4h, so if you pick this one, make sure you’re well prepared for it.

5. The Instagram mission

Yes, it’s officially 4 tours that they offer, but while floating on the 7th or 8th lake, trying to get a semi decent shot of the beautiful formations, we were told it’s also possible to book a photography tour to Calvary hall! Most of the guides are also cave photographers and they organise photography tours upon request. If you opt for this kind of tour they will provide LED lightning and show you all the best spots and angles.

Are you a cave lover like us? What was your favourite underground adventure so far?