Qutub Minar (English: The Qutub Tower; Urdu: قطب مینار), also known as Qutb Minar and Qutab Minar, is the tallest minar in India, originally an ancient Islamic Monument, inscribed with Arabic inscriptions, though the iron pillar has some Brahmi inscriptions, and is a UNESCO World Heritage Site. Located in Delhi, the Qutub Minar is made of red sandstone and marble. The tower has 379 stairs, is 72.5 metres (237.8 ft) high, and has a base diameter of 14.3 metres, which narrows to 2.7 metres at the top storey. Construction was started in 1192 by Qutub-ud-din Aibak and was completed by Iltutmish. It is surrounded by several other ancient and medieval structures and ruins, collectively known as the Qutub complex.