Akka Mahadevi caves are located on the ranges of Nallamalai Hills in Kurnool district, Seemandhra. There is evidence to believe that the caves have been in existence since the prehistoric times. In fact, the caves have played a pivotal role in the history of the town.

The cave has obtained its name, for it is believed that the famous 12th century philosopher and lyricist from Karnataka, Akka Mahadevi did penance and offered prayers to a Shivalingam that was naturally existent deep inside the very same cave.

The Akka Mahadevi caves are naturally formed caves and are located very near to the upstream of the river Krishna. The main cave has a naturally formed rock arch that is considered a geographical marvel. The arch measures approximately 200x16x4 feet and has no support of any kind at all. Tourists are attracted more to the arch than to what lies inside the caves. The rocks, without doubt, are the most attractive things inside the cave especially since they are proven to be as old as life on earth.

Source:

http://www.nativeplanet.com/srisailam/attractions/akka-mahadevi-caves/