The world's largest stone astronomical observatory, Jantar Mantar was built between 1728 and 1734 by Maharaja Sawai Jai Singh II — a warrior king who was also a brilliant astronomer. The site contains 19 massive geometric instruments including the Samrat Yantra, the world's largest stone sundial at 27 meters tall, which can tell time to an accuracy of two seconds. Each instrument was designed to measure different astronomical phenomena — celestial altitudes, azimuths, and ecliptic coordinates — and they remain functional nearly 300 years later. A UNESCO World Heritage Site since 2010.

What makes this place special

The world's largest stone sundial at 27 meters tall, casting a shadow that moves visibly at 1mm per second, telling time to an accuracy of 2 seconds.

Two hemispherical marble sundials representing inverted maps of the sky, where the observer stands inside the bowl-shaped cavity to make observations.

A set of 12 instruments, one for each zodiac sign, used to determine celestial coordinates — among the most unique astronomical instruments ever created.