Postonja Cave
The Postonja Cave, an enormous network karst cave and cavern system, is located forty-five minutes to an hour from Ljubljana driving south on E61 towards Trieste, Italy. The best way to get there is driving, but you can take a bus or hire a tour (which is what we did). Our coach tour cost us 93€ each and we were eight people total, a very manageable group size.
The Cave Tour
The tour is fairly well managed and is split into a train ride tour, which brings you deep into the mountain; and, a walking tour inside the cave system, which explains the geology and processes going on in the cave itself. They also explain some of the fauna that lives in the cave, as well as the ecology. The entire tour from entrance to exit is about one and a half hours. The temperature in the cave system is around 50°F, so bring a jacket or sweater, if you are inclined to get cold. I wore a short-sleeved shirt and was fine, though the train ride was a bit chilly due to the breeze.
Below is a set of short video clips recording the train tour, and a slideshow of the walking tour. Both are in order of when they were taken. I took more than enough photographs because it is such an amazing thing to see and how often does anyone actually go underground for anything?
If you ever get a chance to go, it is well worth the trip. It is one of the largest cave networks in the world, and the second longest in the country of Slovenia.
The Train Ride Tour
The Walking Tour