This is a historic site.located on sansad marg,delhi. Jantar Mantar is primarily a collection of 13 architectural instruments and there are huge curved terracotta buildings, it has a giant playground which makes for great photo opps. ‘Jantar Mantar’ may mean the equivalent to ‘abracadabra’ in Hindi. This was constructed in the year 1725 for scientific purposes. This is the earliest of Maharaja Jai Singh II’s five observatories. It’s dominated by a huge sundial and houses other instruments plotting the course of heavenly bodies. Indian have to pay an entry fee of Rs 5 and foreigners have to pay entry fee of Rs. 100. Open from 9:00am to dusk.