There are a lot of places to visit in Istanbul, and one of the greatest pleasures is simply walking through the streets between those places; however, here is my Top Ten Must See Sights (in no particular order of preference):
TOPKAPI PALACE -- Serene gardens, exquisitely decorated pavilions and the intriguing Harem.
THE BLUE MOSQUE -- Beautiful artistry of construction and decoration, both inside and out.
HAGIA SOPHIA -- A magnificent feat of architecture, with a dome that seems to float in the air above the interior space.
BASILICA CISTERN (Yerebatan Sarayi) -- Eerie, haunting, unusual, fascinating.
SULEYMANIYE MOSQUE -- Calm, peaceful and harmonious, with fine masonry and decoration.
GRAND BAZAAR -- Bustling, energetic, noisy and great, great fun.
BOSPHORUS CRUISE -- Watch minarets, mosques, yalis and villages slide past.
THE HIPPODROME -- Marvel at the obelisks and imagine the chariots racing around this oval in front of cheering crowds.
ARCHEOLOGICAL MUSEUM -- Wonderful statues and mosaics, plus the amazing Alexander Sarcophagus.
MUSEUM OF TURKISH AND ISLAMIC ARTS - a fascinating history of the development of art techniques and styles including wonderful calligraphy plus kilms and carpets.
KRIYE CAMII MUSEUM (ST. SAVIOUR IN CHORA) - amazing Byzantine mosaics, detailed and beautiful.
GALATA TOWER -- Fantastic views over the Bosphorus, the city, and beyond.
Quick Tips:
Istanbul is a fantastic place and everyone I met was polite, courteous and friendly, but, especially if a single female traveller, you may find you get a lot of attention.
In my experience, most of it was friendly -invitations to visit shops, asking if you wanted a guide etc.. If you aren't interested, just politely decline. Don't get angry or be rude. Dress appropriately and respect the customs and conventions of the country you are in. What might not stand out on Oxford Street may stand out in Sultanahmet. Walk purposefully and at night stick to main, well-lit roads. Advice that pertains to a lot of places, not just Istanbul.
You will get stared at, but just ignore it. If things do go further, a loud and firm "No" or "Don't do that please." usually works. Be careful, be aware, but don't let it stop you from having a good time.
A Short History:
The city of Byzantion was founded, reputedly, in 667 BC by King Byzas and soon grew to be a successful city state. In 64BC it became part of the Roman Empire and was re-named Byzantium.
When Contsantine became ruler of the Roman Empire in AD 324 he moved the capital of the Empire to Byzantium which soon became known as Constantinople. Over the next thousand years Constantinople was the centre of the Byzantine Empire and prided itself on its art and culture. It was also during this time that some of the most remarkable architectural sites in the city were built including Hagia Sophia, the Basilica Cistern and the Hippodrome.
On 29th May 1453, after a 54 day siege, Sultan Mehmet II entered Constantinople. The city was re-named Istanbul and the reign of the Ottoman Sultan's began. In 1479 Topkapi Palace was completed. During the reign of Suleyman the Magnificent (1520-66) the royal architect Sinan designed over 200 mosques and other buildings.
During the tulip period of Sultan Ahmet III (1703-30) western clothes became fashionable for the first time.
After the massacre of the janissaries (the Sultan's personal guard and elite fighting force) in 1826 reforms to government and society were instituted.
After the First World War the Ottoman Empire was in serious decline. The Turkish War of Independence began in 1920 and in 1922 the Sultanate was abolished. The following year Turkey was declared a secular republic and Mustafa Kemal Pasa ("Ataturk") became President.
Best Way To Get Around:
Walking -- Choose a district, arm yourself with a good map and set off!
The tram system around Sultanahmet is very good.
Taxis are very cheap by British standards. They are really useful if you get hopelessly lost and your legs are too tired to take you any further!
Now there are low-cost flights to Istanbul more people seem to be flying into Sabiha Gocken Airport. Information on how to get from the airport into Istanbul seemed a little sketchy and, when we arrived, a lot of the things we'd read as suggestions i.e. getting a bus to the ferry terminal, seemed not to be feasible. So here is my suggestions based on our experience in October 2006
I'd suggest taking the Havas Bus to Taksim - there should be one outside the terminal as their departure times tend to coincide with flights - you may have to wait for a little while on the bus before it departs - tickets cost approx. 8 YTL for the journey, pay the representative on board
From Taksim either walk or get a taxi to your hotel if in the Taksim area. Uou can also take a taxi to Sultanahmet - it should cost about 10-15 YTL, however, the more fun and cheaper option is below!
If you are staying in Sultanahmet or surrounding area then walk to Taksim Square then take the Funicular (look for the big M sign signalling the Metro/Funicular)to Kabatas (1.3 YTL per token which can be bought inside the Metro/Funicular station). Kabatas is where the tram terminates so - for another 1.3 YTL token, which can be bought from the booth marked jeton, you can take the tram all the way to Sultanahmet and from there walk to your hotel.
Other options from the airport seemed limited (apart from taxi, which at 90-100 YTL is rather expensive) - we tried to get a bus to take us to one of the ferry terminal so we could get the boat across to Eminonu but couldn't find one
Boat -- along the Bosphorus or over to the Asian side, taking a boat is a trip in itself.