Mrzla jama near Bločice v2.0

Lower COVID-19 restriction over the Summer 2020 allowed us to continue the exploration in Mrzla Jama near Bločice village. By continuing the exploration over the "muddy slide" we got to a big chamber that was hiding the entrance to the fifth siphon, which we explored to the first sidemount restriction. A dry continuation at higher elevation (~ +10 m) to the East was also explored. "Beautiful passage" is highly decorated with dozen of smaller lakes with still water. It ends with a collapse at d. 830 m but several vertical openings offer promising leads.

Suhadolca 2.0

This year's update includes new survey data and the extension of EOL to 1690 m by Simon Burja and Sebastjan Gantar in October 2020. The map itself has also been turned (North now facing "up"), its cross-section adjusted and extended profile sections added. The geometry of the cave forced us to cut the extended profiles into smaller sections in keep the overall map size reasonable. The current EOL ends with a small, but passable sidemount restriction, awaiting new explorers.

Vranja jama v1.0

Vranja Cave is another karst spring that feeds the Cerknica Lake at high water. The cave is closed to the public because of one peculiarity. When the temperatures drop in the fall, the frogs from the surrounding area move to the cave and hibernate there at milder and constant temperatures, which is unique event globally. It is because of this migration that entry into the cave is only possible with the permission from ARSO (Slovenian Environment Agency). We used the warm part of the year to explore this cave. Years ago, divers made their way into this cave, but were stopped by a very unfriendly restriction in the opening meters. Fortunately, after that, the cave opens and continues deeper. Even in the summer one can encounter a couple of frogs and tadpoles in the cave.

Suhadolca v1.0

Suhadolca is one of the karst springs that fill Lake Cerknica in winter months. The entrance is on the southern side of the lake, and the cave continues below Javorniki mountain range. It is a submerged tunnel, which is partly accessible to non-divers in the summer. That is why we record the first cartographic records in the 1968. For cave divers, the cave is of particular interest due to its low depth and excellent visibility in the winter months, which is a rarity in our country. In 2018, the cave was explored and surveyed up to 1600 m in length. It is the longest fully submerged tunnel in Slovenia.

Mrzla jama near Bločice v1.0

Mrzla jama near Bločice is a water cave on the edge of the Bloke plateau. Water from a wide area collects in Farovščica ponor and disappears underground. On its way to Cerkniško polje it comes to the surface in Mrzla jama for a moment. From there, most of the water flows towards the lower springs of Šteberščica and Žerovniščica, and only partially towards the spring in Podlož and the well-known Cross cave (https://ojs.zrc-sazu.si/carsologica/article/view/147/137). The first cartographic entry of the cave dates back to 1972, when the cavers explored the first upstream siphon and reached the first chamber (90 m into the cave). Then, in 2001, Igor Vrhovec and Matej Mihajlovski dived into the second siphon and explored the cave to a length of 128 m, but they did not find a continuation at that time. In 2019 and 2020, we continued with the research and precisely measured and plotted the cave up to a total length of 423 m. The cave continues.