Tear yourself away. This is your last full day in Cairo, and you should spend the rest of it walking the medieval Islamic city. Have your guide and driver escort you to the southern end of the quarter's Ibn Tulun Mosque. Built between a.d. 876 and 879, it is the city's oldest functioning Islamic monument and magnificent in its severe simplicity and scale. Immediately adjacent is the Gayer-Anderson Museum—a fascinating old house where a British army doctor who was an avid art collector lived from 1935 to 1942.

Drive from here to Bab Zuweila, the only remaining southern gate of the medieval city of Al-Qahira ("The Victorious," from whence Cairo was derived). Your guide will still be with you, but the car and driver should go wait at Bab al-Futuh, one of the two northern gates. You'll be walking from now on. Start by climbing either of the two minarets at the top of the gate. It's worth the effort for the old-city views, a sea of seemingly crumbling houses punctuated by domes and minarets—snap away. Next stop is Al-Azhar Mosque, with its vast white-marble-floored central courtyard. Founded in a.d. 970, it was once one of the world's foremost centers of learning, and today its sheikh is the highest theological authority for Egyptian and Sunni Muslims. (Women must wear head scarves—supplied for visitors at the door.)

Hungry and tired? Ask your guide to walk you—all the while pointing out the other notable mosques, mausoleums, and madrassas—to the Naguib Mahfouz restaurant (5 Al-Badistan St.; 20-2-590-3788; entrées, $12–$22). Named for Egypt's late Nobel laureate in literature, it's the safest bet for Western stomachs in this part of town. Instead of sitting in the formal dining rooms, opt for a table in the up-front snack area, overlooking the alleyway running between Al-Hussein Mosque and the gold souk.

You are in the middle of the Khan al-Khalili market—part tourist trap, part the real thing. Bid farewell to your guide after lunch and spend the next few hours exploring on your own, slowly snaking your way north. Try your skills at bargaining (gold jewelry? Egyptian cottons? alabaster vases?), and take in the boisterous, crowded, congenial, and utterly exotic scene—men balancing large crates of freshly baked pita on their heads, others hawking tamarind or licorice juice, enormous glass tanks on their backs. Don't worry about getting lost—that's sort of the point.

Connect with your driver at the Bab al-Futuh gate for the ride back to the Hilton. You have barely scratched the surface of what is one of the world's most historically and culturally fascinating cities, but your impressions will be vivid and long-lasting. End the day with a light dinner at any of the hotel's restaurants—you must be at the airport before six tomorrow morning.