The Quwwat-ul-Islam is best known for its tower of victory, celebrating the Muslim conquest of India. It is built of red sandstone, gray quartz, and white marble, but is probably inspired by the iron "Pillar of the Law" that stands on the site. Built in the Mauryan dynasty in the 6th century, it is the only piece of the temple that stands in its original location. Qutb built around it when he constructed the mosque. Although made of iron, it has resisted rust for over 1,500 years, evidence of the Mauryan's superb metallurgical skills.