They run in a nearly north–south alignment, parallel to the Coromandel Coast for close to 430 km between th rivers, Krishna and Pennar.

Its northern boundaries are marked by the flat Palnadu basin while in the south it merges with the Tirupati hills.

These rocks are among the oldest in the world and have been formed as a result of large scale volcanic activity hundreds of millions of years ago.

The indigenous population consists of the Chenchus, a forest dwelling tribe who have remained cut off from the modern world even today.

A state highway and the Nallapadu-Nandyal line of the Guntur railway division pass through the hills.

The primary exports of this region are forest produce like timber waste, honey and molasses.

Srisailam on the River Krishna is the site of a large hydroelectric power project as also an ancient temple dedicated to Lord Shiva.

It was built by the Gajapati kings of Orissa for irrigating about 420 km2 farmland by damming a narrow opening between two adjoining hills and later renovated by queen Vardarajamma of Vijayanagara kingdom in the 16th century.

Rajasekhara Reddy, with two pilots, a chief security officer and secretary went missing in the Nallamala forest.

After nearly twenty four hours of search by police, para military, Indian Army, Indian Air Force, India Space Research Organization personnel among others, the chopper was located in a mangled and charred state on the top of the 800 ft. Pavuralla Konda (Doves' hill).