The Jantar Mantar is a collection of architectural astronomical instruments, built by Maharaja (King) Jai Singh II at his then new capital of Jaipur between 1727 and 1734. It is modeled after the one that he had built for him at the Mughal capital of Delhi.
The name is derived from jantar ("instrument"), and Mantar ("formula", or in this context "calculation"). Therefore jantar mantar means literally 'calculation instrument'. This observatory has religious significance, since ancient Indian astronomers were also Jyotisa masters.
The observatory consists of fourteen 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 and related ephemerides. Each is a fixed and 'focused' tool. The Samrat Yantra, the largest instrument, is 90 feet (27 m) high, its shadow carefully plotted to tell the time of day. Its face is angled at 27 degrees, the latitude of Jaipur. The Hindu chhatri (small cupola) on top is used as a platform for announcing eclipses and the arrival of monsoons.
The instruments are in most cases huge structures. The scale to which they have been built has been alleged to increase their accuracy.
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.
Today the observatory is a popular tourist attraction.
Jantar Mantar is monumental examples in masonry of known instruments but which in many cases have specific characteristics of their own.
Click here for Photo Features