 The Jantar Mantar observatory , constructed in 1737 , is located above the ghats along the Ganges , and is adjacent to the <unk> and <unk> Ghats and near the palace of Raja Jai Singh of <unk> . While less equipped than the observatories at <unk> and Delhi , the Jantar Mantar has a unique equatorial sundial which is functional and allows measurements to be monitored and recorded by one person . 
