Jantar Mantar in New Delhi is much in the news today, but how many of us are aware of its history? A monument conceived to measure the movements of celestial bodies has become a place where citizens seek to measure the distance between the promises of the state and the realities of their lives. Built to interrogate the heavens, it has become a forum for interrogating those who govern us. Its history is a reminder that monuments do not remain imprisoned in the purposes for which they were constructed. They acquire new meanings as the societies around them change.
Jantar Mantar was built in 1724 by Maharaja Sawai Jai Singh II of Jaipur, a ruler whose interests extended well beyond the conventional preoccupations of kingship. Fascinated by mathematics and astronomy, Jai Singh was dissatisfied with the astronomical instruments available to him. He believed that their limitations compromised the accuracy of celestial observations. He therefore commissioned the construction of massive masonry instruments, designed to measure the positions and movements of heavenly bodies with greater precision. Delhi's observatory was the first of five that he established, the others being at Jaipur, Ujjain, Varanasi and Mathura.
What makes Jantar Mantar remarkable is not merely its antiquity, but the intellectual ambition it embodies. The Samrat Yantra, an immense sundial, was designed to determine local time. The Jai Prakash Yantra used hemispherical structures to establish the positions of celestial objects, while the Ram Yantra helped measure their altitude and azimuth. Each structure translated an abstract mathematical problem into a tangible instrument. By enlarging the instruments and constructing them in durable masonry, Jai Singh sought to reduce errors of observation and obtain more dependable astronomical measurements. The observations made at Delhi contributed to the preparation of the Zij Muhammad Shahi, a set of astronomical tables intended to improve the calculation of celestial positions.
Was this a breakthrough for its time? The answer requires a distinction. European astronomy had already been transformed by the telescope and by developments in heliocentric theory. Jai Singh's instruments largely belonged to the older tradition of positional astronomy, which relied on naked-eye observations and mathematical calculation. Their achievement lay in improving that tradition, not in replacing it with an entirely new understanding of the universe.
The tragedy is that the growth of the modern city, the construction of surrounding buildings and the difficulty of preserving the instruments under their original observational conditions have compromised their astronomical utility. Yet Jantar Mantar has not become irrelevant. It has acquired another life. That transformation began decisively in 1993. Delhi's traditional arena for large public demonstrations had been the Boat Club lawns near India Gate, close to Parliament and the principal government offices. The enormous farmers' agitation led by Mahendra Singh Tikait in 1988 was held there. As governments sought to regulate such gatherings, the Boat Club became increasingly restricted. Jantar Mantar emerged as an alternative, more manageable venue for demonstrations.
For more than three decades**,** Jantar Mantar has been a recurring destination for those who wanted to be heard by the government. In 2011, Anna Hazare's anti-corruption hunger strike helped ignite the India Against Corruption movement, which subsequently contributed to the emergence of the Aam Aadmi Party. Tamil Nadu farmers came to Delhi in 2017 to draw attention to agrarian distress and mounting debt. In December 2019, demonstrators opposed the Citizenship Amendment Act. In 2023, leading Indian wrestlers, including Vinesh Phogat, Sakshi Malik and Bajrang Punia, protested against Wrestling Federation of India chief Brij Bhushan Sharan Singh, raising allegations of sexual harassment and demanding accountability. Students, workers, farmers, political parties, civil-society groups and individuals pursuing causes of public concern have all used the venue.
These protests did not belong to one political party or ideological persuasion. Governments of different political complexions have faced demonstrations there. Of course, the right to protest cannot mean the right to inconvenience everyone without limit. In October 2017, the National Green Tribunal ordered a halt to protests at Jantar Mantar, citing concerns including noise, pollution and public inconvenience. In July 2018, the Supreme Court rejected a blanket prohibition, emphasising the need to balance the rights of residents with the constitutional freedoms of peaceful assembly and expression.
There is, however, a new and significant development. On October 12, 2026, Delhi Police withdrew Jantar Mantar's status as a designated protest venue, naming Ramlila Ground, Burari Ground and CBD Ground in East Delhi as alternatives. The decision has already been challenged in the Supreme Court and Delhi High Court. Thus, as this column is written, the future of Jantar Mantar as an officially designated site for dissent is contested.
This brings us back to the monument itself. A monument built to measure the heavens has become a place where a democracy measures itself. Whether Jantar Mantar continues officially as a protest site or is replaced by more distant venues, the question it poses—what is the truth?—will remain.
Pavan K Varma is an author, diplomat, and former member of Parliament (Rajya Sabha). The views expressed are personal