Jantar Mantar Jaipur

Jantar Mantar is an observatory built by Maharaja Jai Singh II and is the second in the series of five observatories that he built. The name Jantar Mantar comes from Sanskrit words yantra meaning instrument, and mantra, for chanting; hence 'the chanting instrument'.

Jantar Mantar has fourteen major geometric devices for measuring time, predicting eclipses, tracking stars in their orbits, ascertaining the declinations of planets, and determining the celestial altitudes and related ephemeredes. Each devise is a fixed and 'focused' tool.

Built with local stone and marble, each instrument at Jantar Mantar carries an astronomical scale, marked on the marble inner lining.  Bronze tablets, extraordinarily accurate, were also used to make the calculations. Jantar Mantar is a national monument of India.

"An excursion through Jai Singh's Jantar is the singular one of walking through solid geometry and encountering a collective weapons system designed to probe the heavens."  From G.E. Kidder Smith. Looking at Architecture. p98.