Started in 1644 and finished in 1658, the "Friday Mosque" (the main day of prayer for Muslims), stands on a hill facing the Red Fort. The mosque's main entrance, the eastern gate, is reached by crossing the open-air market of Meena Bazaar and wending your way past a whole host of objects on sale to pilgrims and Indian tourists. A monumental staircase leads to the gate, which boasts a deep iwan (a vaulted area which acts as an entrance). Don't miss the prayer hall which is adorned with fine inscriptions from the Koran.