The Kapalı Çarşı has been on this site since Mehmet II built it after the conquest, with over 3,500 shops spread across 60 covered streets. You should walk through it for the spectacle — the light, the noise, the sheer scale — but don't feel obliged to buy. Prices are higher here than in the surrounding streets, though real bargains in cloth and textiles do exist if you look carefully.
The Bedesten (inner market) at the core of the bazaar is the oldest part and the most atmospheric; it deals in antiques and precious metals. The hans around the perimeter — Büyük Valide Han in particular — are worth finding for their Ottoman courtyard architecture. The bazaar opens Monday to Saturday from around 8:30am to 7pm, closed Sundays.