Ancient Stone Riddles is an introduction to the fascinating but less-known monuments called megaliths in the context of the Indian subcontinent. The book seeks to present the current understanding among archaeologists and other researchers in a lucid manner to the general reader, while stimulating thought on the many questions that linger about these remnants from our distant past and the people and cultures that built them. It also discusses recent research about the knowledge systems possessed by the megalith builders, including the possibility that some of these monuments were erected to observe celestial cycles.