Turkey's largest city is a 2010 European Capital of Culture filled with the treasures of a glorious past from the Roman and Ottoman empires, while straddling the Bosphorous Strait where Europe meets Asia.
Reuters correspondents with local knowledge help visitors to get the most of out of a 48-hour visit.
6pm: Start your visit in Galata, on the European side of the Bosphorus. Take the Tunel funicular up the steep hillside, and then head down Galip Dede Caddesi to the Galata Tower. The cylindrical structure dates from the 14th century, when it was built to defend the Genoese colony in Constantinople. The lift-accessed viewing gallery offers a broad view across the waters of the Golden Horn inlet to the old city and the Sea of Marmara.
7pm: Stroll to Istiklal Caddesi, Istanbul's main shopping street, which runs through the Beyoglu neighbourhood.
In the 19th century the area was the city's principle European quarter, and the thoroughfare is lined with fine apartment blocks in the Parisian style. International boutiques stand cheek-by-jowl with purveyors of Turkish delight and pastries, while Denizler Kitabevi is stocked with antique maps and prints of Istanbul. Keep an eye out too for the antique tram and the church of St Mary Draperis at No. 429.
8pm: Still on Istiklal, eat at 360 a restaurant perched in the penthouse of an old apartment block with a view of Istanbul's former embassies. The menu offers a modern riff on traditional Turkish cuisine, with mezes, sushi and the prospect of Death by Chocolate to follow.
10.30pm: If stamina permits Babylon in Beyoglu has built up a reputation for live music in Istanbul in winter, while shipping out to the Aegean in the summer months. Founded in 1999, acts from Patti Smith to Afrika Bambaata have stopped by. Elsewhere Jazz Stop and the Nardis Jazz Club are a way into a different scene.
9am: Start in the historic peninsula, the rough triangle of land between the Bosphorus and Golden Horn that forms the heart of imperial Istanbul. A stone's throw from Sultanahmet tram station take in the Blue Mosque. Commissioned by Sultan Ahmet I and famed for its six minarets, the mosque's English name comes from the thousands of colored tiles that line the interior.
10am: Head across At Meydani Park - once the site of rambunctious Roman chariot races in the ancient city's Hippodrome - to Aya Sofya, the greatest of Istanbul's Byzantine monuments. Built as a church in the sixth century by the Emperor Justinian, and converted to a mosque after the Muslim conquest, for centuries the interior of Aya Sofya was the largest enclosed space in the world. Don't miss the mosaics of the virgin and various Byzantine potentates, as well as a depiction of the Seraphim Angel recently unveiled after 160 years behind plaster.
11.30am: Take Alemdar Caddesi to the Topkapi Palace, the residence of the Ottoman Sultans from the 15th to the 19th centuries. Among the series of low pavilions and enclosed courts are the private quarters of the Harem, once the cloistered haunt of the some of the world's most mysterious women. Elsewhere find exhibits of embroidered regal robes and paintings. Adjacent Gulhane Park, once the extended gardens of the palace, is now a pleasant place to walk too.
1pm: Return to the waterfront in Eminonu and dine on the fishermen's fresh catch, fried al fresco and packed in bread and salad. In good weather sit outside to watch the passing vessels heading to and from the Black Sea along the Bosphorus, one of the world's busiest shipping lanes.
2.30pm: Venture into the Basilica Cistern, close by the Topkapi Palace in the heart of Sultanahmet. Built in Byzantine times as a subterranean water supply and neglected for centuries, a host of columns support the cistern's roof. Renovated in the 1980s, the interior is dramatically floodlit and featured in the 1963 James Bond film From Russia With Love.
4pm: Hop on the tram to Cemberlitas and dive into the winding alleyways of the Grand Bazaar. Supposedly the world's largest; its countless stalls stock everything from jewelry to counterfeit denim. If you grow tired of declining carpets, stop off at one of the numerous cafes for a glass of sweet black tea.
8pm: For supper take a boat to Kiz Kulesi a tower on an islet close to the Asian shore of the Bosphorus. Known variously as the Maiden's or Leander's tower, the restaurant here offers spectacular views back across the waters. Athenian general Alcibiades built a first structure on the site in 408 BC, and the current building featured in the 1999 Bond film The World Is Not Enough.
9am: Back on the European shore, visit the Dolmabahce Palace, where the Ottoman Sultans relocated to from Topkapi in the 19th century. Armenian architect Karabet Balian and his son built the vast pile between 1843 and 1856 in the European style. Their creation sports a 36-metre-high throne room with a four and a half tonne chandelier, donated by Queen Victoria. Mustafa Kemal Ataturk, the founder of the Turkish Republic, died here in 1938.
11am: South along the waterfront from Dolmabahce stands Istanbul Modern, the city's contemporary art collection. Founded in 2004 and housed in an 8,000 square-metre renovated warehouse, the museum's permanent exhibition, New Works, New Horizons, looks at the evolution of contemporary art in Turkey, while food is available on the terrace.
2pm: Back in the old city the Suleymaniye Mosque, close by the Istanbul University campus, is the work of Mimar Sinan, one of the finest Ottoman architects. Completed in the mid-16th century, the mosque's dome is over 50 metres high. Nearby stands Kanaat, a restaurant renowned for its rendering of the bean dish kuru fasulye.
4pm: Unwind with a traditional Turkish bath at the celebrated Cagaloglu Hamami in Sultanahmet. Built in 1741 and regally appointed, the bathhouse claims Kaiser Wilhelm and Florence Nightingale as former patrons.