Jantar Mantar: From astronomical observatory to landmark protest site

The Delhi Police on Monday (October 12, 2026) announced that Jantar Mantar has been denotified as a protest venue. The decision followed recommendations made by a committee constituted by the Ministry of Home Affairs to identify alternative sites for demonstrations.

“Three new venues, namely Ramlila Ground, Burari Ground and CBD Ground in East Delhi, have been designated for the organisation of protests and demonstrations,” the police said in a statement

Also see: Anti-CEC protests, October 12, 2026 | Live updates

Here is a look at the history of Jantar Mantar, how it evolved into one of the capital’s most prominent protest sites, and some of the major demonstrations held there in recent years.

An 18th-century monument

The Delhi Jantar Mantar, originally known as Yantra Mantra, was built by Maharaja Sawai Jai Singh II of Jaipur as an astronomical observatory at the behest of Mughal emperor Muhammad Shah. Constructed around 1724, it relied on naked-eye observations, with its instruments, or yantras, providing remarkably accurate readings.

Built of brick rubble and finished with lime plaster, the observatory comprises four principal instruments: the Samrat Yantra, Ram Yantra, Jai Prakash Yantra and Mishra Yantra. Its primary purpose was to compile astronomical tables and predict the movements and positions of the Sun, Moon and planets. The name “Jantar Mantar” is derived from the words for instruments and calculations.

The Delhi observatory was the first of five Jantar Mantars established by Jai Singh II. The others were built in Jaipur, Ujjain, Mathura, which no longer survives, and Varanasi.

In addition to the four principal instruments, the complex contains 14 geometric devices used to measure time, forecast weather, track planetary movements and determine celestial altitudes. These fixed structures were designed to minimise the effect of vibrations and were carefully aligned to specific directions.

Delhi’s protest landscape

Jantar Mantar was not always Delhi’s preferred venue for protests. Earlier, the Boat Club lawns were the focal point for major agitations, including the anti-cow slaughter demonstrations and mobilisation during the Ram Janmabhoomi movement. Subsequently, the Ramlila Maidan emerged as a key venue where thousands gathered to voice their opposition to government policies. It was also the site of the India Against Corruption movement, which captured widespread public attention.