Jantar Mantar is an astronomical observatory with masonry instruments, built in 1724 by Maharaja Jai Singh II of Jaipur. It houses a huge sundial and other instruments intended to show the movements of the sun, moon etc. This massive salmon colored structure is only a short stroll down Sansad Marg (parliament street). A short stroll down Parliament Street from Connaught Place, is a strange collection of salmon-coloured structures called Jantar Mantar, consisting of several strange looking constructions which are infact very accurately and scientifically devised astronomical instruments for carrying out an organised study of celestial bodies in absence of the telescope. It is also known as the Yantra Mandir. A huge sundial known as the Prince of Dials dominates it.
Jantar Mantar contains four chief instruments - The Samrat Yantra - a simple equal hour sun dial. The Ram Yantra determining the position of the sun and also those of moon, planets and stars. The Jai Prakash gives local time, the sun's declination and the zodical sign or group of the stars on the meridian. To the north of the Samrat Yantra is the Misra Yantra, which is a combination of four scientific gadgets.