During excavations in the 1980's on a mound of earth in the jungles

 During excavations in the 1980's on a mound of earth in the jungles 1 km. North of the temple where it was believed that some information lied buried about the Lord's transformation into rock, a very rare phenomenon of two different sets of rocks connected together in the form of a thin link was found. This formation is known to exist elsewhere only at the 4 fingers of Texas and somewhere in Australia. This is pretty small in size relatively but what makes it unique and astounding is that nowhere in rock formations known to exist on the Indian soil have been found to be of this type and also, the height of The Lord confirms exactly to the distance of the pinnacle of the arch from the foot of the same! Also, two other formations excavated along with resemble the celestial conch and the discus that are the Lord's possessions. These have not been carved even remotely. They are formed naturally very mysterious indeed! This geological arch is a very rare spectacle in the world. This arch (older than the Jurassic age) is 25ft in length, l0ft in height. Pilgrims must make it a point to visit this wonder of the world during their Tirumala trip. No buses are available. A private vehicle or a 20-minute walk from Sri Varahaswamy Temple brings you here.

Source : http://www.tirumala-tirupati.com