Pod RB explorations in Kolkina dupka 2007 – to present days


With Pod RB’s official establishment in 2007 we were motivated to find a region and/or a cave for further exploration. Bulgaria’s caves and karst regions have been well explored and not much was left to explore.

We chose Kolkina dupka as our future project where we would invest our time and energy.

Reasons for choosing Kolkina are:

  • It was close – as bunch of teenagers and students we couldn’t afford long distance travelling nor we had the means to do it, i.e. we didn’t have cars
  • Due its vertical character – we were keen on practicing and implementing more of the alpine techniques we were learning, alpine speleology was, and it is still perceived, as exciting
  • Had promising potential – based on the previous research in Ponor mountain, Kolkina was pointed as having the potential to lead to much bigger discoveries

In 2007 was our first visit to Kolkina, then its depth was -67m and length 46m. With our knowledge, experience, resources and equipment this was challenging enough for us.


So far we have 3 main breakthroughs there and they are as follows:

I (2009)

At the known bottom and end of the cave, a narrow passage was dug further, which took us at the beginning of a 40m shaft. The new volume was quite promising but at the bottom there was nothing, apart from a tiny crack with variting air current.

The following years were not exciting, not exciting at all. Here we spent 4 years with many questioning our sanity and common sense. We were committed to work here and make this project our utmost priority, convinced that such a cave, in such a region, doesn’t end just like that. Moreover, this was the period when we developed our Kolkina mythology, dreaming and visualising the theoretical potential beyond.

II (2013)

The success came in 2013 when we managed to pass, little we knew but this was going to be the first prove in Kolkina, that with hard work and dedication we can go further!

The cave beyond was mainly developed in a meander with constant water flow. Narrow passages, few short pits and water. It takes some 3 to 4 hours to reach a small chamber amid the meander, where now is Bivouac I (-267m, 1 227m). The next barrier was here, a narrow part just next to the bivouac. Much further and deeper now, with way less comfort, here we spent 4 years.

III (2016) 

In December 2016 Kolkina proved for a second time that persistence is always rewarded. This time it would have taken us much longer to explore what we reached. Indeed, 5 years after this discovery, we are still exploring it.

So far we managed to survey 15 555m (in total), reaching -543m. With few different rivers, various directions of development, many climbs and a key point at -543m we are still kept busy.

There is still much left to search and to discover, the explorations in Kolkina require longer periods. Reaching Bivouac II can last up to 12 hours, from where long hours are needed for reaching the furthest parts of the system.


With Kolkina we grew as individuals and as speleologists. We owe a lot to this project, it shaped and developed our club, educated and gave experience to our team members, proved that hard work and big dreams are paying off.

Explorations in Kolkina are continuing! We hope and work for another big discovery and with the huge contribution of the newer generations we believe that it just a matter of time.

A short video from one of the most challenging parts here: