654877bd_erials_Science_and_Engineering__Significance
[Date] 400 (estimated) [Candidate Moment] Iron smiths forge and erect a seven meter high iron pillar in Delhi, India. [Significance] 
Defies deleterious environmental effects for more than one and a half millennia, creating an artifact of long-standing materials science and archaeological intrigue.
Greatest Moments in Materials Science and Engineering
Significance