The Jantar Mantar monument of Jaipur, Rajasthan is a collection of nineteen architectural astronomical instruments, built by the Rajput king Sawai Jai Singh, and completed in 1738 CE. The observatory consists of nineteen instruments for measuring time, predicting eclipses, tracking location of major stars as the earth orbits around the sun, ascertaining the declinations of planets, and determining the celestial altitudes and related ephemerides. News Nation tried to reveal the secret behind the largest stone dial.