9.The construction of the Delhi Iron Pillar, now located at the Quwwat-ul-Islam mosque in New Delhi was constructed in which period?
As per Natya-darpana (by Vishakadata), the Iron pillar had been put up by Chandragupta II himself after defeating Vahilakas. He designated that pillar as a memory of the victory. The pillar is made of 98% wrought iron and has stood more than 1,600 years without rusting or decomposing.