The Golden Horn is the estuary that cuts inland from the Bosphorus along the north side of the historic peninsula, dividing European Istanbul into two. For centuries it served as Istanbul's natural harbour — the Byzantine chain strung across its mouth to block enemy ships was a major defensive barrier. The shores have been cleaned up and pedestrianised over the past 20 years, and a walk along the waterfront from Eminönü to Eyüp, passing the old city walls, the Balat neighbourhood, and the Fener Greek quarter, is one of the best half-day walks in the city.
The Haliç bridge and the ferries that cross it give good views of the Golden Horn's length. At its head, Eyüp Sultan Mosque — one of Islam's most sacred sites in Turkey — draws pilgrims year-round. The cable car to Pierre Loti Café above Eyüp (named for the French author who wrote about Istanbul from this spot) gives elevated views back over the Horn.