Welcome to the Hollow Mountain!
On this page you will find information about the annual JSPDT/ICCC expedition to Slovenia, with details on what to bring, how to get there and what to expect on the mountain.
What is the Expedition?
Since 1974, the JSPDT (a Slovenian caving club) have been exploring Sistem Migovec, and alpine cave system in the Julian Alps. ICCC joined them in 1994 and we've been going every summer (with a couple of breaks) ever since. We drive to Slovenia, carry all of our food and equipment up to 1800 m above sea level and camp for four to five weeks on top of the mountain. We explore the cave system beneath the surface in small teams, and tread in places no one has ever been before. We survey and map the cave, entering the data into a 3D model that now covers 37 km of cave passage, with the deepest point 975 m below the surface.
For the history of the expedition up to 2006, read our book, The Hollow Mountain
A lovely small country (almost 2 million people) between Adriatic Sea and Alp mountains. It is a democratic country on the South of Middle Europe. Border countries are Italy, Austria, Hungary and Croatia. Slovenia is part of UN, NATO and EU, since 1991, when Slovenia vote for independence from Yugoslavia. The Euro is the official currency.
Beside Slovenians there are about 15% of other cultures living in Slovenia, especially from former Yugoslavian countries. The official language is Slovenian. Near Hungarian and Italian border also Italian and Hungarian are spoken.
In all 12 official regions a different dialect is spoken. But there is more than just 12 dialects – Almost every village speaks different Slovene version! Many words are from German, Hungarian or Italian language – but spoken in a Slovene version. So, even if you know Slovenian you might find not to understand it in many regions. But no worries – the Slovenian school system is very good – everybody has learnt some English. It is friendly and safe country. You can camp and hitchhike everywhere. Locals will help foreign visitors.
Tolmin is the closest town to Migovec, the mountain where the expedition is based. The local club (the JSPDT) is based here and it's a wonderful place to hang out.
Tolmin is located in Slovenian Triglavski national park and its area provides majestic waterfalls, fabulous river pools, the exceptional and inimitable Soča river, hidden ravines, mysterious springs, gorges and canyons, caves, unlimited trekking on nearby hills and mountains. There are also countless little corners emanating the charms that would make an attentive visitors pause for a while and watch in admiration.
The Tolmin caving club. The only real tourist cave nearby is Zadlaška or Dantejeva cave, where the Renaissance poet Dante Alighieri supposedly found inspiration for the terrifying images of his Inferno. Also nearby is the cave Mala Boka, but only for more fit tourists. In Tolmin area there is the deepest cave in Slovenia called Čehi II (depth: 1502m) on mountain Rombon in Kanin area near Bovec. Sistem Mala Boka is on the second place with 1319m depth. On the 7th place is Sistem Mig with depth 970m. The longest caves in Tolmin are our own Sistem Mig (37,200m) and Pološka jama, which is 10,800m long, is in the 6th place in Slovenia. The ICCC expedition will be on a mountain called Tolminski Migovec (Mig).
How to get to Tolmin
If you need help planning transport to or from Tolmin it's worth contacting an experienced club member for help - there are some subtleties involving buses not running on certain days and other logistics that makes their advice useful.
The minibus is the cheapest options and involves the least effort. Everyone pays for the minibus regardless (we have to get all the kit to Slovenia!) and although it's a long journey, you will get there without having to negotiate any public transport. Highly recommended for novices.
Buses in Slovenia
Many of the route descriptions below use Slovenian buses. These can be infrequent and the time depend a great deal on what day of the week it is - Sundays are usually not good days to travel! In the big timetable, the buses have a code to say which day they run on, the translation is:
D weekdays and Saturdays; D* weekdays; NP Sundays and holidays; NPS last day of holidays in the days of the school year; PSPP Mondays, Wednesdays and Fridays in the days of school holidays; SO Saturday; ŠPA weekdays in the days of school holidays from 1.9. to 30.6 .; ŠP1 weekdays in the days of school holidays; Š1 weekdays in the days of the school year; V every day; V1 daily from 1.7. to 31.8 ;
Flying to Trieste
Ryanair fly from London Stansted to Trieste Airport (actually near Gorizia in Italy). Ryanair don't fly every day, and the flights can get into Trieste quite late - not very good for getting to Tolmin, so check carefully. Currently they are quite cheap: £40 without any hold luggage.
From Trieste Airport take the bus to Gorizia. Then you have three options:
Bus to Nova Gorica bus station (very frequent), and take the bus to Tolmin (pg 58). This is quite easy, but be aware that there are fewer buses on Saturday and very few on Sunday.
Flying to Venice Marco Polo
Note there are two 'Venice' airports, Marco Polo and Treviso - the latter is cheaper to get to, but more difficult to get to Tolmin from. For both airports you want to take public transport to Gorizia, and follow the directions above for travel from Trieste - either take the bus or the train and another bus to Tolmin.
Flying to Ljubljana
Easyjet do flights from Gatwick ands Stansted which are surprisingly expensive from London (£90 one way) but quite cheap the other way (£40). From the airport, take the bus to Ljubjana, and then you have three options:
Train from London to Most na Soci
If you don't like flying, or want a more leisurely journey, you can take the train to Ljubljana with an overnight stop in Munich, and then take the train to Most Na Soci. From Most na Soci, take the bus to Tolmin (pg 59). Jack Hare did this in 2015 and enjoyed it, though it can be more expensive than flying.
Here is the rather long annual kit guide for freshers going to Slov. There is no TLDR, you should read it all and make sure you are prepared.
Places to buy stuff: Decathlon, Mountain Warehouse, Primark, TK Maxx, online (but be careful you know what you're buying!) You can always ask someone for help!
- Frame Rucksack (at least ~60L, 80 is better, with good anatomical back!) ~£100
- Rollmat (a few spare in stores)
- Sleeping bag (3 season + ). A cheap, big, synthetic is absolutely fine and probably most comfy on the uneven ground. A compression bag is really useful to pack it down small.
- Tent – make sure you've got something arranged (bring your own/share/use club tent)
- Water bottle - at least 1 L for the hike up, or a platypus type device. A small bottle (500 ml) is nice for underground.
- (Optional) Dry Bags. Big ones for your clothes/electronics on the surface (tent leaks happen). Bin bag liners are an alternative. Lots of carrier bags good for separating dirty from clean stuff, keeping caving kit in
- (Optional) Knee support - tubular bandages or other, particularly if >22 Yrs - very expensive to buy in Tolmin
- (Optional) First Aid kit - club has a few, though ideal is to get a crush-proof beaker and assemble your own from spare bits 'n' bobs (include contact lens, personal medication, Compeed if you get blisters etc.).
- (Optional): Sleeping bag liner (polyester or silk, Thermarest is a good brand). Very lightweight, adds warmth, and draught-proofs exposed feet/shoulders on warmer nights. For those who don't wash, stops you sticking to the sleeping bag. ~£10-£15 for polyester.
- Walking Socks: Thick wool of polyester socks NOT cotton, at least two pairs. Wear instead of wetsocks underground. Get some liner socks and never have blisters again!
- Walking boots or good walking shoes, with a proper (Vibram) sole.
- Thermals - cheap: Uniqlo's ''heatmax', expensive: Helly Hanson.
- Sun hat (which also doubles as a rain hat...)
- Sun glasses - high altitude means UV damages eyes quickly
- Warm Hat (or two, cheap acrylic from the market / Primark is perfect)
- Goretex jacket / waterproof. Cheapest to get a cheap (heavy) goretex from TkMax for warmth in evenings, and a lightweight waterproof to keep in rucksack (when walking up / down) in case it rains.
- (Optional) Duvet jacket / down jacket nice to have a super warm layer to put on for when you're sitting around in the evening (synthetic ones from mountain warehouse are cheap/good but take up space, Decathlon are also good).
- (Optional) Synthetic tshirts – super nice and cheap though. Makes sweating not unpleasant (and you will sweat on the walk up)
- (Optional) Long sleeved shirts - good for keeping the sun off your arms and looking super-stylin'.
- (Optional) Durable sandals - great for wearing around the bivi when your walking boots are too sweaty.
- Knife - Petzl Spatha or a simple swiss army knife.
- Head Torch - Petzl Tikka is the (expensive) classic (~£20-30). Or get a rip off one on eBay (~£5 for something not a total heap of junk). Important for walking round at night not just in cave.
- Whistle - good for signalling above and underground.
- Thin fleece hat (to wear under helmet) / (balaclava). Very useful when waiting for others to rig.
- Fleece neck warmers (same as above, potentially also just get balaclava)
- Gloves – Thick rubberised work gloves are good, try and get some that fit well. You can buy good ones in Slov, but don't count on it.
- Thermals - as for above ground, these will be for wearing underground.
- (Optional) Cave pants - highly recommended, synthetic form fitting pants help with comfort, warmth and style.
- (Optional) Glove liners – silk/fleece for warmth or comfort.
- (Optional) Your own helmet + super-duper expo light. Ideal time to get your own if you're planning on caving a lot in the future. As you might have noticed, the entire club has Dave Wilson's Bisun make.
- (Optional) A thermos flash - great for hot vitaminski underground!
Note on clothes: Temperature is from ~just subzero (but feeling lower at altitude) to 30C in the valleys. Layers are brilliant. Shorts are ace - especially nylon ones. Trousers that turn into shorts are ideal and extremely stylish. Thermal long trousers + tracksuit bottoms/ 'technical' fast dry trouser outers are typical evening attire, with thermal layers on top + fleece/wool pullover / jackets.
- Books/Kindle - Find ones with really small text / get an e-Reader:).
- A hobby Why not learn to sew a reusable tea-bag, devise a better mousetrap, learn to play guitar, or recorder, or solve rubic cubes, or learn to juggle, while on expo?
- MP3 player - good for the walk / in your tent. Bring spare, cheap earbuds!
- Battery pack – don't count on the solar panels, your phone is the lowest priority for electricity!
- Phone – there is some dodgy 3g signal floating around on the mountain so it can be worth bringing a phone to check exam results/tell parents you're not dead etc. Don't forget a charging lead!
Things you don't need on mountain
- A laptop or tablet - you won't be able to charge it anyway as there's no 240 V AC, and even if there was, there's no spare electricity.
- Cutlery/Plate (loads on mountain)
- Soap (no spare water to wash) - but baby wipes are nice!
- Mirror (don't torture yourself)
- Any questions: ask someone!
- Don't worry too much. Many notable idiots have survived on the mountain.
- All your personal kit not including caving kit should fit into your rucksack.
Life on the Mountain
Everyone's experience of expo is different, but this section is meant to give you a flavour of what living on the mountain is like, and most importantly to give you a reasonable expectations for your first expedition.
The first few days of the expedition are spent carrying food and equipment up the mountain. We park the minibus at the mountain hamlet of Ravne, and unload it into a barn provided by a friendly local family (The Klobučar family, also known as the Skalars [farmers]). Then you load up your personal items and tent, and start the walk 1000 m up the mountain. The walk begins in the woods with winding switchbacks, before breaking out into high alpine meadows at the Shepherd's Huts, where there is fresh water and hopefully some snacks. After this, the path climbs rapidly up the side of Migovec, crossing scree slopes and patches of nettles before arriving on the plateau, an undulating landscape dotted with shakeholes, dwarf pine and sunbathing cavers.
After pitching your tent, you might decide to go back down and get your caving kit, or some food. You'll return to the bivi in time for dinner, cooked on a petrol stove, and probably sleep soundly after a day of walking up and down the mountain. On subsequent days there's still lots to bring up - food, rope, bolts, drills, survey instruments and snacks! The carrying is an essential part of expo - not only is it the only way to get equipment up the mountain, it also gets you fit for the expedition to come. By the end of expo you'll notice how much faster you are walking up and down the mountain, proof of your improved fitness.
Soon, however, the caving will begin. First the caves need to be rerigged - the rope is often left in the cave, but pulled up to stop water damaging it. You'll join an experienced caver on a 'bounce' trip, going down to rerig and back out again, without doing any exploration. Again, this is essential to improve your skills and get you used to long days out. The pushing front in Primadonna is 600 m below the surface, but most caves in Yorkshire are only a hundred metres deep. You'll be exhausted after a day of caving, but you'll notice immediately how much your SRT improves.
Back on the surface you can watch the sunset with the rest of the expedition at the Sunset Spot, a patch of grass overlooking the mountains to the west where the sun goes down. As the moon rises each night you'll see it wax and wane - if you stay for four weeks you'll see an entire cycle of the moon, something you've probably never looked for before. Every night the food is hot, filling and delicious and a range of 'cocktails' satisfy your thirst, supplemented by popcorn and delicious puddings.
It's not all about the deep caving - each year we do a lot of work surface bashing, looking for new cave entrances on the surface. Often these have to be dug out with trowels and dig trays, and it's a fun day out going across the plateau looking for new leads. On some days you might just want to relax, reading a book or preparing food, adjusting the tarpaulins that catch our drinking water or digging snow to make slushies with. You can walk down to Tolmin and spend the night at the youth hostel if you need a shower or the company of non-cavers, or you could walk across to a mountain hut and buy a huge wheel of the local cheese - sure to make you popular in the bivi!
If you do well on the bounce trips, you may find yourself wanting to go pushing - looking for new cave passage underground. Pushing trips are organised ad-hoc, and it helps to be keen if you want to do it. More experienced cavers often will have some idea where to look from studying the maps, discussing with others or some crazed intuition. We usually push in teams of two, and you need to go with someone who knows the way, so you'll need to find a more experienced caver to take you. They will be more than happy to have someone along to carry all the tinned fish and rope, but they also want to train you up so that you can lead other new cavers in future years. Because there are only a few experienced cavers, you might not be able to go pushing every time you want to - be patient, stay keen and you will get the chance. If you can't go pushing one day, make sure you have a chance to go caving anyway, to boost your SRT skills and make any exploration you do more enjoyable. If someone isn't willing to go pushing with you because they're too exhausted, you might still be able to tempt them to do a bounce trip into some other part of the system.
At the end of expo, everything has to come back down the mountain, and there are usually around three days of carries to load up the minibus before we drive back to the UK. You'll smell awful, have strange bruises and cuts covering your entire body, but you'll have done something remarkable with your summer that very few people ever get to experience, and as the minibus drives back through Europe you'll already be planning to join us again next year.
Bivi: A shakehole (depression in the ground) where we cook, eat and doss on the plateau. People usually hang out here if they're not sleeping, caving or getting some chapters in.
Bounce trip: A trip down and back up a known part of the system, with no intention of pushing.
Doss: To sit in the bivi, doing very little activity and recovering from caving or accidentally thinking about caving.
Expo: The Expedition
Hollow Mountain: A nick-name for Migovec, the mountain which contains the cave system we explore.
Lead: A potential new cave passage.
Pushing: Checking out a lead to see if it goes anywhere.
This work is licensed under a Creative Commons Attribution 4.0 International License.