This observatory was constructed by Savai Raja JaySingh between 1725 and 1730 AD. Similar observatories were constructed by Raja Jaysingh at four other places-Delhi, Jaipur, Mathura and Varanasi. Samrat Yantra, Nadivalaya Yantra, Digansha Yantra, Shanku Yantra and Yamyottarabhitti yantra are the main instruments constructed in this observatory. Motions and orbits of the planets are studied through these instruments. On this count, people call it yantra-mahal also. This observatory was renovated by Madhav Rao Scindia. The Then Maharaja of erstwhile Gwalior state in 1923 AD. Astronomical studies of the planetary motions are still conducted in this observatory and an ephemeris (i.e journal showing daily speed and position of planets) is published of every year. In this way this is the only observatory among the observatories of Jaysingh where Masonic instruments are even today utilized for astronomical studies.