Jantar Mantar, Delhi was built by Maharaja Jai Singh of Jaipur in the year 1724. Five observatories were established during his reign in the early 18th century. The observatories are located in Jaipur, Varanasi, Ujjain and Mathura. The main objective was to compile astronomical tables and accurately predict the movements of the planets, the Moon and the Sun. By 1867, Delhi’s Jantar Mantar had deteriorated significantly. Much later, the Government of India took several initiatives to restore the heritage observatory and promote it as a tourist destination in Delhi.