Tirumala is located 3,200 feet (980 m) above sea level and covers an area of approximately 10.33 square miles (26.8 km2). Surrounding the hills are seven peaks of Seshachalam range, Eastern Ghats namely Seshadri, Neeladri, Garudadri, Anjanadri, Vrushabadri, Narayanadri and Venkatadri. The temple of Sri Venkateswara is on the seventh peak (Venkatadri).
At 21 km point on the Tirupati – Tirumala Ghat road, there is a major discontinuity of stratigraphic significance that represents a period of remarkable serenity in the geological history of the Earth. This is referred to as Eparchaean Unconformity. This Unconformity separates the Proterozoic Nagari Quartazite and Archean granite representing a time gap of 800 Ma. In 2001, the Geological Survey of India(GSI) declared the Eparchaean Unconfirmity to be one of the 26 “Geological Monuments of India”.
Silathoranam, a Natural arch and a distinctive geological wonder is located in Tirumala Hills at a distance of 1 km from Tirumala Venkateswara Temple. The Arch measures 8 metres in width and 3 metres in height and is eroded out of quartizite of Cuddapah Supergroup of Middle to Upper Proterozoic(1600 to 570 Ma) by weathering agents such as water and wind