As a natural and extremely secures harbor, the Golden Horn has played an important role in the development of Istanbul. The inlet separates the European shore into two. It is approximately 8 km long and widest part is the entrance from the Bosphorus. Two streams drain into this inlet at its far end.

Across from St. Sophia built in the 17th century by the architect Mehmet, this is known as the BLUE MOSQUE because of its magnificent interior of blue Iznik tiles. It was built between 1609 and 1616, during the rule of Ahmed I. Like many other mosques, it also comprises a tomb of the founder, a madrasah and a hospice. The Sultan Ahmed Mosque has become one of the most popular tourist attractions in Istanbul.

This ancient basilica, built by Constantine the Great, in the 4th century and reconstructed by Justinian in the 6th century, is one of the architectural marvels of all time. In 1453, Constantinople was conquered by the Ottoman Turks and Sultan Mehmed II ordered the building to be converted into a mosque. The bells, altar, iconostasis, and sacrificial vessels were removed, and many of the mosaics were eventually plastered over. The Islamic features  such as the mihrab, the minbar, and the four minarets outside — were added over the course of its history under the Ottomans. It remained as a mosque until 1935, when it was converted into a museum by the Republic of Turkey.

The great palace of the Ottoman sultans from the 15th to the 19th centuries, housing an exquisite collection of crystal, silver and Chinese porcelain; robes worn by the sultans and their families, miniatures, the Holy Mantle; Chamber of Sacred Relics.

There are several documents suggesting the name of the bazaar was first "New Bazaar". However, due to the fact that many spices were imported via Egypt in the Ottoman period, the name "Misir Carsisi" was favoured by the public.The structure was designed by the chief court architect Koca Kasim Aga, but completed by architect Mustafa in 1660. The air here is filled with the enticing aromas of cinnamon, caraway, saffron, mint, thyme and every other conceivable herb and spice.

This Bosphorus suburb has an interesting ethnic history in which church, synagogue, and mosque coexist peacefully in its narrow streets.Today it is a trendy gathering place for the young and hip,with art  galleries,chic cafe – bars, and boutiques selling antiques. On warm Saturdays and Sundays artisans display their wares in the narrow streets in an impromptu arts-and-crafts show. At the water's edge by the ornate mosque called the Ortaköy Camii. The Etz Ahayim Synagogue, has been here since 1660 though the current building dates from 1941, when the old one was destroyed by a disastrous fire.

Both shores of the Bosphorus have their Ottoman palaces. Every emperor needs some little place to get away to and 30-room Beylerbeyi palace was the place for Abdül Aziz (1861-76). Mahmut II had built a wooden palace here,but like so many other wooden palaces it burned down. Abdül Aziz a spent lot of time here, as did other monarchsand royal guests, for this was, in effects, the sultan's guest quarters. The palace's last imperial guest was none other than the former sultan, Abdül Hamit II, who was brought here to spend the remainder of his life (from 1913 to 1918)

Here at the narrowest part of  the Bosphorus. Mehmet the Conqueror had this fortress built in a mere four mounths during 1452, in preparation for his planned siege of Byzantine Constantinople, Mehmet the Conqueror ordered each of his three viziers to take responsibility for one of the three main towers. Once completed,Rumeli Hisarı, in concert with Anadolu Hisarı on the Asian shore just opposite,controlled all trafic on the Bosphorus,and cut the city off from resupply by sea from the north.

Perched above the village are the ruins of Anadolu Kavagı a medieval castle with seven massive towers in its walls. First built by the Byzantines, it was restored and reinforced by the Genoese in 1350,and later by the Ottomans. As the straits are norrow here, it was a good choice for a defensive site to control traffic. Two more fortresses, put up by Sultan Murat IV,are north of here.Exposing a panoramic view of istanbul, Bosphorus and Black sea from the best point of view.

Poyrazkoy is one of the villages nearest to the Black Sea and is located on the Anatolian side of the Istanbul. From the minaret a bridge leads out to the gun emplacements and ammunition stores and a great view. Although the village is located on top of a hill, there is a road leading to the beach just before the village. Poyrazkoy is an excellent place for a break or for shelter while sailing from Istanbul to the Black Sea.