Far off the beaten path, accessible only 4x4 in fact, are Botswana's Gcwihaba Caverns, a fantastical series of caverns filled with stalactites, stalagmites, and bats. Thousands of bats.
Once a potential explorer reaches the isolated Gcwihaba Caverns, it is not a challenging descent in terms of spelunking, but it has unique challenges of its own. Even the Botswana tourism website warns to be prepared for a storm of flying rodents if you make too much noise.
The main chamber of the dolomite caves, named Drotsky's Cavern after the the first European to be shown the cave in 1934, is a massive clearing in the stone in which bats hang from all the walls. The cave systems are home to at least three distinct species of bat, all of which are harmless, but all of which inhabit the caves in force.
Archeological artifacts have also been found in and around the caves, suggesting that they were once used as shelter for prehistoric man.