The fort’s massive red sandstone walls, which stand 75 feet (23 metres) high, enclose a complex of palaces and entertainment halls, projecting balconies, baths and indoor canals, and geometrical gardens, as well as an ornate mosque. Among the most famous structures of the complex are the Hall of Public Audience (Diwan-i-ʿAm), which has 60 red sandstone pillars supporting a flat roof, and the Hall of Private Audience (Diwan-i-Khas), which is smaller and has a pavilion of white marble.
An earlier red fort had been built in Old Delhi in the 11th century by the Tomara king Anangapala. The Quá¹b Mosque now stands on the site.