Jantar Mantar - An observatory of Astronomical Instruments
Jantar Mantar is one of the most popular attractions of Jaipur. Between 1724 and 1734 A.D. Maharaja Sawai Jai Singh II constructed five observatories in the country. Jantar Mantar in Jaipur is the most famous of the five observatories, other four are in Delhi, Varanasi, Ujjain and Mathura. In Sanskrit, Jantar Mantar is used for 'Magical Devices' and this huge observatory was place here to measure the harmony of the heavens. Jantar Mantar comprises multiple buildings of unique form, each with a specialized function for astronomical observation. In 1901, the observatory was renovated but it still gives the accurate time, location of the sun, the degrees of latitudes and longitudes, the movements of the stars, planets and satellites and the correct timing of eclipses. The observatory with its amazing combination of geometric forms has grabbed the attention of architects, artists and art historians world wide.


Maharaja Sawai Jai Singh II was a learned man and an astronomer who was highly interested in the working of the celestial bodies. The ruler built his first stone observatory in 1724 in Delhi and the Jaipur observatory was built in 1728. It is said that Jai Singh II sent his ambassadors to different parts of the world before starting the construction of these observatories. The ambassadors came back with several manuals and astronomical tables. Besides, they also brought huge data on the advances made in the field of astronomy. One of these manuals was La Hire's "Tables" and Jai Singh II ordered to built the Jaipur observatory according the data available in this manual. Interestingly, when the construction of the Jantar Mantar was completed it was found that the observatory was more accurate than the Table.

Sawai Jai Singh II had the choice of constructing the observatory either with metal instruments or masonry instruments. He discarded the metal instruments and built the observatory with the instruments of stone and masonry that he himself designed.

Instruments in Jantar Mantar
Samrat Yantra : The Samrat Yantra is a large sundial consists of a massive triangle marked with hours and minutes. The left arc shows the time from sunrise to midday while the right arc shows the time from midday to sunset. The time is read by observing the sharpest shadow at the sundial.

Ram Yantra : The Ram Yantra is used to indicate the altitude and declination of celestial bodies.

Jai Prakash Yantra : The instrument locate the positions of the celestial bodies during days and nights. Jai Prakash Yantra is a two hemispherical bowl structure that represents the celestial sphere. It act as a double check on all the other instruments.

Dakshina Yantra : The instrument is used for observing the position and movement of heavenly bodies passing over the meridian.

Large Samrat Yantra : The Large Samrat Yantra is ten times bigger than the Samrat Yantra and gives more accurate time.

Rashivalayas Yantra : This instrument has 12 sundials for 12 Zodiac signs.

Dhruva Yantra : The Dhruva Yantra locates the position of 12 Zodiac signs and also the Pole Star at night.

Other Instruments : Other instruments in the observatory are the Narivalya Yantra, the Jai Singh's seat (the seat of the Observer), the Kranti Yantra, the Raj Yantra or the King of Instruments, the Unnsyhsmsa Yantra, the Chakra Yantra and the Disha Yantra.