Seshachalam Hills

The Seshachalam Hills are hilly ranges part of the Eastern Ghats in southern Andhra Pradesh state, in southeastern India.
Geology.
The ranges were formed during the Precambrian era (3.8 billion to 540 million years ago). Minerals contained in these hills include sandstone and shale interbedded with limestone. The ranges are bounded by the Rayalaseema uplands to the west and northwest, and the Nandyal Valley to the north.
Religious significance.
Tirupati, a major Hindu pilgrimage town is located in the hills. The hills contain seven peaks namely, Anjanadri, Garudadri, Narayanadri, Neeladri, Seshadri, Venkatadri and Vrishabhadri, the highest at about 600 m (2,000 ft) above sea level. The seven peaks are said to represent the seven hoods of Lord Adisesha, the king of serpents in Hindu mythology. The Srivenkateshwara National Park is also located in these ranges. The famous Natural Arch, Tirumala Hills is also a part of Seshachalam Hills, which dates back to the period in between Middle and Upper Proterozoic Eon.
Protected reserve forest.
In 2010, it was designated as a Biosphere Reserve.
It has large reserves of red sandalwood which is used in medicines, soaps, spiritual rituals,etc.