One of the most visited caves in Croatia is the Biserujke Cave, located near the village of Rudine, on the island of Krk. The island is abundant with caves, 54 of them, of which Biserujka is the largest and only one open to visitors. The cave is filled with stenoendemic species, including insects, spiders, centipedes and a rare type of shrimp. As many as 28 species have been detected, six of which do not live anywhere else in the world.
In addition to rich animal life, the cave is particularly famous for its magnificent interior decorated with stalactites, stalagmites, and columns made of calcite. It takes thousands of years to create such cave formations.
Fun fact: it is named Biserujka (Pearly) for according to the legend, the pirates in the Adriatic used it to hide their stolen treasure.