Istanbul’s strategic location is the reason why it is one of the most contested cities in the world.  Its proximity to both Asia and Europe, as well as the passageway to the Mediterranean and the Aegean Sea, made it a significant player when it came to commerce and trade.  It is, after all, an important trade city.  Its control of the narrow channel connecting the Black Sea and the Mediterranean gave it the political clout it enjoyed for years and years.  Yes, during its heyday, all roads led to Istanbul.  This is the important link to the East and West, the North and South.
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Istanbul stands north-west of Turkey’s Marmara Region.  Basically, the 1,500 or so square kilometers of the city is divided into three main parts –by the Golden Horn, the Bosphorus Strait and the Sea of Marmara.  The three bodies of water surround the triangular shape that is Istanbul.  The north side of Istanbul is bounded by the Black Sea, which the Sea of Marmara is the border on the South Side.  It has the geographically unique distinction of being a city that straddles two continents because its eastern side is in Asia while is western side is in Europe.  In between the two halves, you will find the Bosphorus Strait.
turkey bosphorus map
Istanbul also enjoys excellent shelter provided by the hills and the three seas, making it very hard for conquering troops to simply storm in and capture the land.  The geographical make-up also makes for an excellent harbor.

That is why legend relates the story of Commander Byzas, for whom the city was named.  An oracle predicted that he will build his city opposite the land of the blind.  And really, upon setting eyes at the protected peninsula, he came to the conclusion that the people who decided to settle right across it (the early settlers of Kalikow) were indeed blind, as they did not see the potential that lay right under their very noses.
bosphorus map
What is also interesting to know is that Istanbul lies above two tectonic plates – the Eurasian and African plates.  These two meet and press against each other.  Add to this the fact that the city is close to the North Anatolian fault line.  An earthquake in 1894 destroyed some parts of the Grand Bazaar.

You will notice that most of the historic sites are located at the Old City, at Sultanahmet.   This is where you can find vestiges of the glory of the Roman, Classical, Byzantine and Ottoman Empires.  On the opposite side of the Golden Horn are the districts of Beyoglu, Besiktas Galata, Karakoy and Tunel.  Besiktas is where the palace of the last Sultan was located.   On the Asian side are mostly residential areas of upper-class standards.  These are mostly summer houses and posh mansions, which are also called yali.  Here, you will see Uskudar and Kadikoy.  Galata, Taksim and Beyoglu are more on the modern side – business and modern residential areas that house a third of the population of Istanbul.
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