About Jantar Mantar
Jantar Mantar is a collection of nineteen architectural astronomical instruments built by the Rajput king Sawai Jai Singh II. Completed in 1734, it features the world's largest stone sundial and is a UNESCO World Heritage site.
History
Built between 1727 and 1734, Jantar Mantar was constructed by Maharaja Sawai Jai Singh II, who had a keen interest in astronomy. The name 'Jantar Mantar' is derived from the Sanskrit words 'yantra' (instruments) and 'mantra' (formulae).
The observatory consists of fourteen major geometric devices for measuring time, tracking celestial bodies, and observing the orbits around the sun. The instruments are built from local stone and marble, each with a specialized function for astronomical measurement.
The most significant instrument is the Samrat Yantra, the world's largest sundial. Its 27-meter-high gnomon arm stands at a 27-degree angle and casts a shadow that moves visibly at 1 mm per second, or roughly 6 cm per minute, making it the world's most accurate sundial of its size.