Witness the world's largest sundial at Jantar Mantar. There are five Jantar Mantars in India, of which the largest is in Jaipur. A stone observatory, part of the city palace complex, jantar mantar is one of the several other astronomical observatories created by maharaja Swai Jai Singh 2nd.Jai Singh had a passion of astronomy and used astronomical inventions from different of these observatories.
Samrat Yantra, Jai Prakash Yantra, Disha Yantra, Rama Yantra, Chakra Yantra, Rashiwalay Yantra, Dingash Yantra, Utaansh Yantra are the instuments or sundials. The primary purpose of the observatory was to compile astronomical tables, and to predict the times and movements of the sun, moon and planets.