These are 2500 year old pillow lava formations located on the route from Bangalore to Hubli (Karnataka state, India). Closest landmark: Chitradurga fort

One of the world's best examples as per Geological Survey of India (GSI), the pillow lavas at Mardihalli, near Chitradurga, Karnataka, India were formed when part of the Indian Subcontinent was underwater and molten, hot lava bubbled over, and was quickly cooled into chubby, pillow-like shapes. The GSI site indicates that these structures have been dated to 2500 million years ago, and are found in the schist belt of the Dharwad Group