In 1734, the year of its completion, the Jai Singh Observatory was the last outpost of medieval science. From the outside, the eighteen fixed observational instruments look more like playground apparatus than sighting devices, but they were used to measure the position of the sun, stars and planets. Built by Jai Singh, the first Maharaja of Jaipur who founded the city in 1727, the observatory is one of a handful. Jai Singh, fulfilling a lifelong interest in mathematics and astronomy, built observatories in Delhi, Jaipur, Ujjain, Mathura and Benares. The Jaipur observatory is the largest and best preserved of these.