Rajko's cave (Serbian: Рајкова пећина) is a cave in the eastern part of Serbia.
The cave is located at the spring of Mali Pek, 2 km from town Majdanpek in Eastern Serbia. It is 120 km away from the E75 Beograd - Niš highway and 200 km from Belgrade. It is a river cave through whose entire length flows the Rajko's River (Рајкова река). During the summer river channels inside the cave can become dry.
The total length of the cave is 2,304 meters while the tourist path is 1,410.5 meters long. Air temperature is constant - 8 degrees Celsius and relative humidity is 100%. The cave consists of two physically separated caverns: an underground river channel and a spring cave, both of which have two floors. A series of attractive groupings are found in Rajko's Cave: The Egyptian goddess, the Snail, Stump with Mushrooms, Sleeping Bear and several cave halls. The Rajko's cave has the highest quality of cave ornaments. During the cold months of the year large number of bats are living in the remote parts of the cave.
There is a permanent organized guide service at Rajko's Cave. Tours last 60 minutes. Visiting hours are from 9.00 a.m. to 6.00 p.m. (from April 1 to October 31), and in winter period by appointment. Tours can be booked by visiting tourist office in the center of the nearby town Majdanpek. There is a well equipped tourist camp for tents, a cafe, parking and nice lake near the entrance of the cave.