Silathoranam near the Chakra Teertham is a wonderful spectacle, formed out of a natural rock formation that earns it its archeological value. The source is said to be dedicated to Lord Venkateshwara idol since the rock appears to be like the hood of a serpent, a conch and a discus.
One of the three sites of its kind in the world, this arch formation is categorized as pre-Cambrian that dates back to millions of years. The other two sites are the one that cut through the headland of the Dalradian Quartzite in UK and the Rainbow Arch Bridge of Utah in the United States of America.
Silathoranam is said to have been found accidentally by geologists while excavating a geological fault on the Tirumala Hills. This wonderful phenomenon of nature has inspired various schools of thoughts, some of which hold the view that it could be the effect of a wave action from oceanic transgression or intensified climatic settings, corrosion or that it might have been carved out of quartzite. This natural splendor is now a national monument protected by the state government.
