Krishna's Butterball is a giant granite boulder about 6 metres in diameter, balancing on a smooth slope with a contact area that looks impossibly small. It sits in the main monument area, between the beachside Shore Temple and the inland Pancha Rathas, and is impossible to miss — it draws crowds of visitors posing against it for photographs that attempt to show the rock "rolling" off their hands.
The name comes from a local story that the rock fell from the sky and is a ball of butter stolen by the god Krishna. Whatever its origin, the geology is real: it is a natural boulder that has been in its current position for at least 1,300 years, as it appears in medieval Tamil literature. You can walk under its lower edge — clearance is about two metres on the downslope side.