Situated on Tirumala, this is a rare geographical arch and the only one of its kind in the whole of Asia. Two other such arches are known to exist in the world - the Rainbow Arch of Utah in USA and the Arch of “Cut Through“ of UK. This is one of the rarest 'geological faults' of India and geologists compute the age of the arch as 1500 million years. This is also a rare geological feature called 'eparchean unconformity'. This natural arch is believed to have formed due to intensified weathering and erosion of stream action and has withstood the torque of nature. The length of this arch is 25 feet and the height 10 feet.