These are two giant boulders leaning against each other, making an archway like formation. You can find them on the left side of the main road when you go from the Underground Shiva Temple towards Hampi village square. The road almost passes through under the stones. Akka-Thangi Gudda means ‘sister stones’ in the local language.
There are many variants of the local folklore how these boulders came into existence. According to one such has it that these they were two sisters and they became stone as a curse when they ridiculed the place.
In the recent past one of the boulders developed a fissure and partly collapsed. It's attributed to the increased vehicular traffic that passes by these twin boulders.