Jantar Mantar is a whole set of unique space structures, constructed on the orders of Maharaja Jai Singh II in Jaipur – the newly formed capital city of Rajasthan. Literally, the name of the Observatory can be translated as "calculation tool". All were built five observatories in different cities of India, but that the Jaipur Jantar Mantar is the largest of all, besides, she has survived better than others.

Originally this building was perceived as a sacred place, as in astronomy at that time was engaged exclusively in the caste of priests.

The complex consists of 14 buildings-appliances giant size, which was used to determine the time, predicting eclipses and weather, determine the distances to celestial objects, etc. Then it was thought that such large dimensions give these devices more accuracy. So in the Jaipur Jantar Mantar are the biggest sundial in the world, the size of which is 27 meters in diameter. Thus, they are in working order and show the exact time.

Today the Observatory attracts many tourists from all over the world. In addition, it is still used by local astronomers to predict the weather, although their predictions are not always true. Besides, this place is often visited by people, who want to learn Vedic astrology, Jantar Mantar is one of the few "survivors" of the Vedic structures.

In 1948, the Observatory was designated a national monument. And in 2010, the Jantar Mantar was included in the list of UNESCO world heritage site.