Introduction Apart from being the capital of India, Delhi is a fascinating city with pleasant contradictions. Comprising of Old Delhi and New Delhi, the city is home to famous tourist destinations like the Laxmi Narayan Temple, India Gate, Jama Masjid, Red Fort, Qutub Minar, Humayun's Tomb, and the vivacious shopping bazaar of Chandni Chowk. One such tourist attraction in Delhi is the Old Fort, also known as Purana Qila in Hindi, one of the most famous monuments in Delhi, India. Background The founder of the Sur Dynasty, Sher Shah Suri, constructed this enormous fort in the 16th-century to defend his most prized possession, Delhi, from the Mughals. In 1539-40, he defeated his arch-rival, Mughal emperor Humayun, in two consecutive battles and nearly brought an end to the Mughal Empire in India by capturing two Mughal strongholds - Delhi and Agra. Though the Purana Qila has not been witness to any major battle, its very existence kept the Mughals away from invading Delhi. But after Sher Shah Suri died in 1545, Humayun recaptured Delhi and Agra with the help of Persians. Humayun made good use of the octagonal red sandstone tower known as Sher Mandal as his library and observatory. Some Mughal historical documents suggest that Humayun died as a result of the injuries he suffered after falling down from the steps of the Sher Mandal. It is being said that the Mughals considering the fort to be a cursed one after the death of the Humayun, and vacated the edifice. As a consequence, the Mughals had to construct a new fort to defend Delhi from foreign invasions. This fort was named Lal Qila, popular known as Red Fort. Description The unique Mughal-Hindu-Afghan architecture of the fort not only attracts tourists from world over, but has also drawn attention of archaeologists and Indian historians. Recent archaeological excavations have exposed evidences of pottery and other pieces of art and handicrafts which throw a new light on the existence of Indraprastha, a historic city mentioned in the great epic Mahabharata. A report by the Archaeological Survey of India suggests that Indraprastha stood on the site where the Old Fort stands today. The historic structure of the Purana Qila, that has stood witness to the periods of anarchy, the rise and fall of empires in Delhi, presently houses the Delhi Zoo, Delhi's largest zoological park, and a Boat club.