pillar of Delhi

The Iron Pillar of Delhi is a famous pillar located in the Qutb Minar complex in Mehrauli, Delhi, India. It is renowned for its remarkable resistance to rust, despite being over 1,600 years old, dating back to approximately 400 CE during the Gupta period.

This six-ton pillar, measuring about 23.5 feet (7.2 meters) in total height, is largely composed of iron with trace amounts of other elements. Metallurgists believe its unique anti-corrosive properties are due to a high phosphorus content, which helps form a protective rust layer. Originally created for a temple dedicated to Vishnu, it is believed to have been moved to Delhi in the 13th century. The pillar is considered a significant object in Indian history and a testament to ancient Indian metallurgy.1