•    Thefirstfew sights are on the right side of the boat.
As the boat pulls away, you're treated to a fine panorama of the Old Town peninsula—made even more dramatic by the boats scurrying around the harbor, and the embankments and streets teeming with people. You see Hagia Sophia first, with its dome and minarets. Sirkeci Train Station is right behind the car ferry dock. As you move along the peninsula, the gardens of Topkapi Palace come into view—including Divan Tower, with the buildings of the Harem complex to its left.
On the waterfront, past the car ferry port, is the Sepetçiler Pavilion (seh-peht-chee-lehr; "Basketweavers"), today a fine restaurant used mostly for banquets.
Within a few minutes, you reach Seraglio Point, the tip of the Old Town peninsula. This is where the Golden Horn ends and the Bosphorus begins. As you get farther away from the Old Town, you will notice the minarets and later the dome of Blue Mosque behind Hagia Sophia. Soon the skyline of old Istanbul will be dominated by domes, minarets, and towers. Add a layer of haze, and you have a magical, mystical-looking silhouette.
A little off Seraglio Point, you can see the end of the Bosphorus—where it joins the Sea of Marmara. Around the base of the Old Town peninsula are intact portions of the Byzantine wall, which fortified the city until the Ottomans conquered it in the 15th century. As the boat turns left, you'll begin to get some good views of Asian Istanbul, across the Bosphorus. The cranes mark the main commercial port of the city. From this angle, the Princes' Islands appear to the south, usually as a silhouette a few miles off Asian Istanbul in the Sea of Marmara. On a clear day, you can even see the southern shores of Marmara.

• Look toward Asia.
You may notice a floating platform in the Bosphorus between Asian Istanbul and the Old Town. This is the construction site of a new eight-mile Metro tunnel, the Marmaray, that will cross under the Bosphorus—giving locals one more way to make the crossing. (Today the only options are by two bridges—both of which we'll see—or by boat.) The new tunnel is expected to open by 2010. Offshore from Asian Istanbul is one of the city's symbols, the old Byzantine tower often referred to as the Maiden's Tower (just left of the harbor, but before  the radar tower. Today this landmark is used asn a lighthouse and a restaurant.
'that's all in Asiafor a while. The boat picks up speed—yes, it'11 go this I list the whole time—and moves closer to Europe. Get settled and start reading ahead. Now focus your attention on European Istanbul (left).
Just after the harbor building ends, you see the clearly marked Istanbul Modern Arts Museum (the gray, blocky, modern harbor-I ront building, sometimes hidden behind parked vessels; then the Academy of Fine Arts. After that you begin in pass residential neighborhoods.
Soon you go by the Kabataş district and its seabus and ferry ports. Beyond that is the Dolmabahce Palace complex, the 19th-century palace of the Ottoman sultan. The first building is the Dolmabahce Mosque, built exclusively for the sultans, and sharing the same eclectic style as the palace itself. Next door is the clock tower, built as an extravagant accessory. Right behind the tower is a soccer stadium that seats 30,000 people—but, since it's ingeniously designed to fit into its surroundings, you barely notice it. Unfortunately, the same cannot be said of the tall glass building above, the Ritz Carlton. The other sore-thumb is the Swiss Hotel, right above the palace.
Centuries-old trees partially block your vision of the monumental gate, to the right of the clock tower, leading to the palace. This also marks the start of a waterfront fence, guarded by soldiers. At the back side of the garden, just before the palace starts, you can see a second massive entryway, built for the sole use of the sultan and his guests.
The first wing of the building, including the tall middle part, was the palace's administrative section, called Selamlik (seh-lahm-luhk). The side gate was for officials and envoys, whom the sultan received in the front-corner rooms, with sweeping Bosphorus views. The next wing was the Harem, or residential section, extending behind the visible section. The building to the right, set apart from the palace, was for guests and palace employees.
Impressive as Dolmabahce is from here, you may notice that a century and a half of humidity and saltwater have taken their toll on the palace's facade. The back, inland side (not visible from here) is even more glum. Though the palace walls facing the Bosphorus are ornate, the back is plain and dull—left undecorated when the sultan ran out of money.
Where the palace fence ends is an abandoned ferry port, named for Barbarossa—the famous pirate-turned-Ottoman admiral. When Barbarossa sailed the seas, the Ottoman armada controlled the entire Mediterranean. The park just beyond the dock, and the mosque behind the park, are also both named for their beloved Barbarossa. There's a larger-than-life Barbarossa statue in the park, and his tomb is in the mosque complex. The fenced park belongs to the Naval Museum.
While you were ogling the palace, you may have noticed the ferry starting to slow down for its first stop, at Beşiktaş (beh-sheek-tahsh). Enjoy your last views back on the Old Town, which is now little more than an outline. While the boat docks, look down into the water, swirling with garbage and jellyfish—two good reasons why you'll rarely see swimmers in the Bosphorus. (s3)