Jantar Mantar of Jaipur is an astronomical observatory built by Sawai Jai Singh II. Besides this one in Jaipur, India owns 4 more Jantar Mantar across different states. Featuring the world’s largest sundials, the astronomical observatory of Jaipur marks its prominence amongst UNESCO’s world heritage sites. Jaipur’s Jantar Mantar comprises of some astounding stone structures which once were used for locating the exact positions of the celestial bodies in space. There are around 19 instruments carved out from stone and brass. As it aids in calculating the local time, this massive structure attracts geographers, architects, and historians. Even time has failed before the brilliance of this engineering marvel. The observatory still holds its significance in the same manner as it did a thousand years ago. The main motive behind the existence of this structure was to gather and study information related to the universe, time and space. The instruments present refers here to those used in the Egyptian study of Ptolemaic astronomy. The observatory is known to work on the principles laid down by the classical celestial coordinates. They are a horizon-zenith local system, ecliptic system, and finally the equatorial system. These three systems aid the researchers and geographers to track the position of the heavenly bodies. Here at the Jantar Mantar Jaipur, you get to witness a hybrid mixture of different astronomical and architectural instruments. The 19 geometric devices present here to contribute towards understanding local time, ascertaining the declination of planetary systems, predicting eclipses, and tracking orbital stars. Besides, it also aids in the determination of celestial altitudes. The entire observatory covers a land stretch of 18700 metres.Samrat Yantra, Ram Yantra, Jai Prakash Yantra, Narivalya yantra, Karnti yantra, Raj yantra, Unnsynhsmsa yantra, Chakra yantra, Disha yantra, Dakshina yantra, and Rasayas yantra are some of the instruments found here. History of Jantar Mantar Jaipur - Sawai Jai Singh II was a renowned scholar of his time. Once a while, Emperor Muhammad Shah assigned him a task to confirm and rectify the currently available data on the position and movement of celestial bodies. Sawai Jai Singh was desperate to refine the tables of ancient Islamic zij to determine the exact time. In short, he aimed to create a well-defined calendar. He was keen on making accurate astrological predictions for the benefit of mankind. To bring his dream to reality, he decided that he would construct Jantar Mantar in the year 1718. For the same, he set out on a mission to extensively study the cosmological principles as laid down by the philosophical findings of Hindu, Islamic, European, and Persian civilization. In this way, five different astronomical observatories were constructed across various states in India. The largest amongst all was built in Jaipur in between the period 1727 to 1733. After that, it underwent frequent renovations with the lapse of time. The available instruments have a broad range of cosmological applications. In the year 2010, this astronomical observatory got featured in the list of UNESCO’s world heritage sites. The architecture of Jantar Mantar Jaipur –The astronomical observatory of Jaipur – Jantar Mantar, is a collection of both astronomical and architectural instruments. In all, you may find around 19 major geometrical devices here. Each one of them has got its own specific application. These devices are used to measure time; ascertain the declination of the planets and the planetary system; prediction of the eclipses; determination of the celestial altitudes, and tracking of the orbital stars. Sheltering so many instruments, the entire observatory extends to a land stretch of 18700 metres. Interestingly, some of the instruments available here are amongst the largest in their own species. The instruments of this astronomical observatory were carved out purely from stone and marble as they have got a tremendous potential to withstand climatic changes. Some of them were designed by Raja Sawai Jai Singh II himself. A few of these instruments were carved out from copper and still are recognised for their undeniable accuracy. In terms of its dimensions, the Jantar Mantar at Jaipur is the largest of all its counterparts present elsewhere in India.