Founded by Emperor Shah Jahan and surrounded by a magnificent 18m-high wall, this fort took 10 years to construct (1638–48) and is rumoured to have had the decapitated bodies of prisoners built into the foundations for luck. It once overlooked the Yamuna River, which has now shrunk to some distance away. A tree-lined waterway, known as nahr-i-bihisht (river of paradise), once ran out of the fort and along Chandni Chowk, fed by the Yamuna.

Shah Jahan never took up full residence here, after his disloyal son, Aurangzeb, imprisoned him in Agra Fort.

The last Mughal emperor of Delhi, Bahadur Shah Zafar, was flushed from the Red Fort in 1857 and exiled to Burma (Myanmar) for his role in the First War of Independence. The British destroyed buildings and gardens inside the fortress walls and replaced them with barrack blocks for the colonial army.

The audio guide tour, by acclaimed company Narrowcasters, is worthwhile as it brings the site to life.