Ali Sadr Cave, Iran
Ali Sadr is the largest water cave in the world and is located 75 km northeast from the city of Hamadan, Iran. The cave is 70 million years old, and was re-discovered in 1963. In the cave there are several large and deep lakes so that it’s possible to visit the cave with a boat.
Resavska cave, Serbia
Resavska cave is located in eastern Serbia, in the limestone hill of Babina Glava. This cave is about 80 million years old and is one of the oldest surveyed caves. Resava cave interior is decorated with numerous channels, pillars and petrified waterfalls. Due to this diversity, Resavska cave is known as Resavska beauty.
Hang Son Doong, Vietnam
Hang Son Doong is the largest cave discovered to date in the world and is located in Vietnam. In this cave there is a small jungle which was formed under the collapsed roof of the cave. It is probably the only rain forest in the cave in the world.