Straddling the Bosphorus, the strait flowing between the Sea of Marmara and the Black Sea, creates a natural north-south its skyline studded with domes and minarets, Istanbul is one of the truly great romantic cities. Its history tracks back from Byzantium to Constantinople to its place at the head of the Ottoman Empire. Today it hums as Turkey's cultural heart and good-time capital.

In this sprawling, continent-spanning city you can tramp the streets where crusaders and janissaries once marched; admire mosques that are the most sublime architectural expressions of Islamic piety; peer into the sultan's harem; and hunt for bargains in the Kapali Çarsi (Grand Bazaar).

Side by side with Old Istanbul you'll find hip bars and clubs, flashy executives, malls and haute cuisine. And then there is a rich arts culture - opera, music, cinema - which nods its head to the Ottoman and Byzantine ways while taking cues from Europe. All this history, hustle and bustle coexists around the spine of the Bosphorus, a constantly busy, heaving mass, dotted with ships and ferries, and providing the link between Europe and Asia. Is where you'll find all the main sights, such as Topkapi Palace, Blue Mosque (Sultan Ahmet Camii), Aya Sofya (Sancta Sophia), the Atmeydani (Hippodrome) and the old city walls.

Aya Sofya (known as Hagia Sofia in Greek and also called the Church of the Divine Wisdom) was regarded as the greatest church in Christendom up until the fall of Constantinople, when it was put back into service as a mosque. The edifice is crammed with fine mosaics and topped by a magnificent dome.

The Blue Mosque is a triumph of harmony, proportion and elegance. 'Blue' because of its stunning interior decorated with Iznik tiles, this mosque is one of the city's largest and busiest. Sultan Ahmet set out to build a mosque that would rival and even surpass the achievment of Justinian. He came close to his goal.

Kapali Çarsi (Grand Bazaar) has been a shopper's Mecca since just after the mid-15th century, when the smallish warehouse was turned into a teeming bazaar by a constant stream of traders, selling everything from carpets to cummin. These days it's the most fantastic, monstrous, labyrinthine and totally manic shopping bazaar you could hope to experience.

Topkapi Palace was the official Sultan’s residence for centuries. It was made by Mehmet I in 1453. You can see the Imperial Council Chamber, the Imperial Treasury, the Sacred Safekeeping Rooms, Baghdad Kiosk, the Tower of Justice and the Harem.

Yerebatan Sarniçi (Sunken cistern), with its 336 columns and a high, vaulted ceiling, is an incredible Byzantine relic that was primarily used to store the city's water. Built in AD 532, it is the largest surviving Byzantine cistern in Istanbul.