The Iron Pillar at Mehrauli (Delhi), famous for its rust-resistant composition, was built during the Gupta Dynasty period, likely around 375-415 CE under Chandragupta II. It originally stood in front of a Vishnu temple in the Udayagiri area near Vidisha (Madhya Pradesh). The Kushan, Maurya, and Satvahana dynasties ruled in different periods and locations.