Rajasthan, India. Ungraded C LOG 2 Jantar Mantar Is Astronomical Observation Site Built In Early 18th Century. It Includes Set Of Some 20 Main Fixed Instruments. Tower Clock. Pigeon Fly In Slow-mo Above Tower Clock. Worlds Largest Stone Sundial, And Is Unesco World Heritage Site. Jantar Mantar Literally Means Calculating Instrument.