The Jantar Mantar is a collection of architectural astronomical instruments, built by Sawai Jai Singh who was a Rajput king. The title of (King) and Sawai was bestowed on him by Emperor Mohammad Shah. Jai Singh II of Amber built his new capital of Jaipur between 1727 and 1734. It is also located in Ujjain and Mathura.
It is modeled after the one that he had built at the Mughal capital of Delhi. He had constructed a total of five such facilities at different locations, including the ones at Delhi and Jaipur. The Jaipur observatory is the largest and best preserved of these. It has been inscribed on the World Heritage List as "an expression of the astronomical skills and cosmological concepts of the court of a scholarly prince at the end of the Mughal period".[1] Early restoration work was undertaken under the supervision of Major Arthur Garrett, a keen amateur astronomer, during his appointment as Assistant State Engineer for the Jaipur District.