Jantar Mantar

Built in 1827 by Maharaja Sawai Jai Singh Ji and  situated in the present day City Palace Complex  this Astronomical  Observatory’s instuments are  made with stone, marble and masonry and  consequently were so accurate that Sawai Jai Singh Ji was able to find errors in the   astronomical tables then in use.Sawai Jai Singh Ji published his own tables in 1723. There are 18 instruments in the Observatory.The largest instrument is the Samrat Yantra.It is a Sun Dial.It is 89 feet high and 148 feet wide and can find the local time with an  error of only a couple of seconds.It is in use till date.Samrat Yantra is used on the full moon night of guru poornima to find out when the monsoon is going to set in and how plentiful it will  be.

Due to the efforts of UNESCO and Archaeological Survey of India, Jaipur Jantar Mantar, has  become  the second World Heritage Site from Rajassthan.In 1985 Keoladeo National Park, Bharatpur,had joined the World Heritage Sites list.