"Tradition attributed the Dhar Iron Pillar to Bhoja, who was well versed in iron metallurgy as is attested by his Yuktikalpataru . The pillar was double the height of the Delhi Iron Pillar and weighed at least one tonne more. It was the tallest and heaviest (7000 kg) pillar in the world."
January 1, 1970
https://en.wikiquote.org/wiki/Dhar_iron_pillar