Jantar Mantar
A Jantar Mantar (जंतर मंतर, Hindustani pronunciation: [d͡ʒən̪t̪ər mən̪t̪ər] ‘calculation instruments’) is an assembly of stone-built astronomical instruments, designed to be used with the naked eye. There were five Jantar Mantars in India, built between 1724 and 1735. All were built at the command of the Sawai Jai Singh II, who had a keen interest in mathematics, architecture and astronomy. A total of five Jantar Mantars were constructed across North India: Jaipur, Delhi, Ujjain, Varanasi, and M
Wikipedia ↗