Jantar Mantar's instruments fascinate with their ingenuity, but Precise observations can no longer be made from here because of the tall buildings in the area.
Jantar Mantar is the name of five historic astronomical observatories that Maharaja Jai Singh II had built between 1724 and 1734 in Delhi, Ujjain, Mathura, Varanasi and Jaipur. Nasīr ad-Dīn at-Tūsī's observatory in Maragha and Ulug Beg's observatory in Samarkand served as models. Wikipedia