1,600 years in the open Delhi air and it STILL won't rust (the iron pillar)

Mehrauli kid, walked past this thing my whole childhood. The iron pillar inside the Qutub Minar complex. ~7m tall, ~6 tons of wrought iron, Gupta era, around 400 AD. probably originally made near Udayagiri in MP and moved here later. the whole deal: it's been standing OUTSIDE, exposed to Delhi mons……