Jantar Mantar (Yantra - instruments, mantra – formulae or instruments for calculation) is an astronomical observatory with masonry instruments which was constructed in 1724. The mathematician and astronomer king, Maharaja Jai Singh II of Jaipur who built this observatory in Dilli, later during 1727 – 1734, went on to build other observatories in Jaipur, Ujjain, Varanasi and … [Read more...]