Mysterious Stone Of The Sky God: Krishna's Butter Ball

This granite rock is over 20 feet tall and weighs over 250 tons. With its width almost equal to its height, it looks like a sphere in some angles but is not a perfect sphere. You can see a lot of people sitting under it which gives you an idea of how big it is. Many people think of this rock as a natural formation. However, such a natural formation is impossible because There is no way it could have come to this shape by erosion, flowing water or blowing wind. You can see that the rest of the area is a smooth hill, and is devoid of any other large rocks. So if its not a natural formation who could have put this here? Even in modern days, moving a 250 ton rock uphill would be a very difficult task and require complex equipment like cranes. How was it done 1200 years ago?