The Jantar Mantar is a collection of architectural astronomical instruments, built by Maharaja Jai Singh II at his then new capital of Jaipur between 1727 and 1734. The observatory consists of 14 major geometric devices for measuring time, predicting eclipses, tracking stars' location as the earth orbits around the sun, ascertaining the declinations of planets, and determining the celestial altitudes. An excursion through Jai Singh's Jantar is a unique experience of walking through solid geometry and encountering a collective astronomical system designed to probe the heavens. The giant sundial, known as the samrat yantra (supreme instrument) is the world's largest sundial, standing 27 meters tall.
