<Tr> <Th> Coordinates </Th> <Td> 26 ° 55 ′ 29" N 75 ° 49 ′ 28" E ﻿ / ﻿ 26.92472 ° N 75.82444 ° E ﻿ / 26.92472; 75.82444 Coordinates: 26 ° 55 ′ 29" N 75 ° 49 ′ 28" E ﻿ / ﻿ 26.92472 ° N 75.82444 ° E ﻿ / 26.92472; 75.82444 </Td> </Tr> <Tr> <Td_colspan="2"> Location of Jantar Mantar, Jaipur in Rajasthan . Jantar Mantar, Jaipur (India) Show map of Rajasthan Show map of India Show all </Td> </Tr> <P> The Jantar Mantar monument in Jaipur, Rajasthan is a collection of nineteen architectural astronomical instruments built by the Rajput king Sawai Jai Singh II, and completed in 1734 . It features the world's largest stone sundial, and is a UNESCO World Heritage site . It is located near City Palace and Hawa Mahal . The instruments allow the observation of astronomical positions with the naked eye . The monument expresses architectural innovations, as well as the coming together of ideas from different religious and social beliefs in 18th - century India . The observatory is an example of the Ptolemaic positional astronomy which was shared by many civilizations . </P> <P> The monument features instruments operating in each of the three main classical celestial coordinate systems: the horizon - zenith local system, the equatorial system and the ecliptic system . The Kapala Yantraprakara is one that works in two systems and allows transformation of the coordinates directly from one system to the other . </P>

Who built the jantar mantar observation in jaipur and delhi