Unofficial: Qutub Minar Delhi

Qutub Minar (also spelled as Qutb Minar, Qutab Minar, Kutub Minar or Kutub Meenar) is the world’s tallest red sandstone tower and a UNESCO World Heritage Site. Located in the Mehrauli area of New Delhi, the tower is one of the earliest monumental structures of Delhi.

Qutub Minar was built in the early 13th century by the slave-emperor Qutub-ud-din Aibak and his successor Shams-ud-din Iltutmish. Aibak started work on the first storey in 1199 AD, which continued for the next 21 years. Around 1220 AD, Iltutmish added three storeys to Qutub Minar. However, lightning struck the fourth storey in 1369 destroying it completely. Firoz Shah Tughlaq, the 19th emperor of Delhi (1351-1388) carried out repairs, replacing the damaged storey with two new storeys.