An ancient iron pillar located inside the Qutb Minar complex in New Delhi has stood for 1,600 years, remaining intact despite being exposed to sun and rain. Standing at 7.2 meters high and weighing 6 tons, the pillar can be found in the courtyard of the Quwwat-ul-Islam mosque in Mehrauli district.
Scientists have been baffled by the durability of the pillar, as structures made of iron typically rust over time when exposed to air or moisture. In 2003, experts at the Indian Institute of Technology (IIT) in Kanpur discovered that the pillar was mainly made from wrought iron with high levels of phosphorus and no sulfur or magnesium, thanks to a technique called “forge welding.”
This ancient method of construction, along with the presence of a thin layer of misawite on the surface of the pillar, has contributed to its longevity. The pillar has become a symbol of ancient Indian craftsmanship and metallurgy, showcasing the country’s ability to forge iron in ancient times.
Despite its mysterious origins and missing statue of Garuda, the mount of Lord Vishnu, the iron pillar continues to be a source of fascination for archaeologists and scientists. In an effort to preserve the pillar, the Archaeological Survey of India has built a moat around it to minimize human impact and ensure its continued protection.