Jantar Mantar, the 18th century observatory with its complex astronomical instruments was built by Maharaja Sawai Jai Singh, the founder of Jaipur between 1710 and 1724. This period is generally known as the dark age of Indian history. The Maharaja built five such Jantar Mantars including one at Delhi. The other four monuments are built at Jaipur, Varanasi, Ujjain and Mathura. Delhi’s monument, however, is historically the most important in all the five.

It is located at Connaught Place, in the heart of the capital. Incidentally, besides being a fabulous tourist attraction, it also serves somewhat like London’s Hyde Park, as the venue of all sorts of protests and demonstrations by individuals, groups and even larger political parties.

As you enter the Jantar Mantar, you find some abstract structures within its premises. They are, in fact, yantras- instruments to track the celestial bodies, plot their course, predict the eclipses and keep the time. There are four yantras-- Samrat, Misra, Jai Prakash and Ram. They tell a lot about the technological achievements under the Rajput kings and their efforts to understand the mysteries of astronomy. These yantras were designed by the Maharaja himself. .

The two pillars standing on the southwest of the Mishra Yantra, or the Mixed Instrument, are used to calculate the shortest and the longest days of the year. It must be interesting to note that one pillar completely covers the other with its shadow in December, while it does not cast any shadow at all in June. Misra Yantra is an ingenious device to accurately predict the time in four other places in the world when it is noon in Delhi.

The sprawling outer area of the Jantar Mantar is dominated by the huge Samarat Yantra or the king of instruments. It gets its name from its huge size and architectural precision. It can tell the local time within four minutes.

The monument was also used as the logo of the 1982 Asian Games. The observatory was declared as a national monument in 1958. It has been preserved as an emblem of Indian astronomical science in the 18th century.

These yantras were illuminated in June 2007. Besides this all the signages were reworked and explanatory designs put up to help the visitors.

Jantar Mantar is surrounded by high-rise office buildings and it beautifully synchronizes with their futuristic looks. The mysterious structures in the Jantar Mantar confirm the accuracy of many astronomical observations. They are used even by the modern scholars of astronomy to determine the positions of the astral bodies. Jantar Mantar represents a perfect synergy between science and religion.