Biserujka Cave is located near the village of Rudine, in Dobrinj on the island. It is arranged for visitors and offers a wealth of cave decorations - calcite columns, stalactites and stalagmites. It consists of several underground rooms. From the time when it was believed that in it was the hidden treasure of a smuggler and with the first curious visitors there began a gradual widening of its narrow passages.

 With a length of about 110 meters, these caves are truly breathtakingly beautiful, with interesting sedimented forms and size of the underground space. The cave temperature throughout the year is from 10 to 13 C, and occasional leaks and moisture occur only after long periods of rain. Maintained and safe paths through the cave are available to everyone, from children to the elderly.

 Endemism of flora and fauna of the cave is very pronounced. In the cave lives six stenoendemic types (narrow endemic to the Kvarner area), and found the remains of bones of cave bear (Ursus spelaeus).