Silathoranam, a natural rock formation, with immense archaeological significance located about 1 km north of the Sri Venkateswara Temple, near the Chakra Teertham at Tirumala. Presumed as the only one of its kind in Asia, the arch measures 8 m (26.2 ft) in width and 3 m (9.8 ft) in height, and it enacts Lord Vishnu’s Shanku, Chakram, Thiruman and his Abhayakaram. It was in 1980s when geologists had found out that two different rock sets are connected through an exceptionally thin link. The assessed geological age of the rock arch is 1.5 billion years.
According to beliefs, this natural rock is associated with Lord Venkateswara as the rock is naturally created in the shape of a serpent’s cover, some associate the shape of the rock with arch, discus and conch. Formation of the arch is attributed to intensified weathering and erosion of stream action that has withstood the torque of nature. This is a rare geological fault which is technically called in the geological idiom as ‘eparchian unconformity’.