Biserujka cave:

We don’t know when the cave system was discovered, all we know is that the oldest cave with writings and signitures was found in 1859.The cave is 110m long, the lowest depth is 12m below the surfice of the earth and 53m below sea-level. 3-5 metre of thick soil layer covers it, and it only gets moistness from the rain. It is a very unusual mountain cave because of its subterranean position. First stalagmit will arise the thinnest ones since they are hollow called “spaghetti”, the water is dripping through these, so one mm stalagmit may take up to 30 years to evolve. The walls are black from the soot  since the visitors were using torches inside the cave. The reddis-greyish colour took shape because of thr iron oxid. The cave fist received lighting after the II World war, and for some time there was an opporunity for groups to visit. They restored it 9 years ago, but then it was left without supervision, people could walk freely in the cave system, causing severe damages. There are 54 caves on Krk island that we know of, but this is the largest and only one that can be visited. You may meet some specific animals in the cave such as: bats, various vermins, snails, spiders, centipede, and some  5mm small crabs that only lives in this cave counts as a real curio.