Sometimes described as 'the crossroads of Europe and Asia', Istanbul - formerly Constantinople - is a vast, heaving metropolis with an imperial history that stretches back for more than 1,500 years. No longer Turkey's capital but still the cultural heart of the nation, this city of 13 million sprawls across both sides of a land bridge spanning two continents.

Istanbul's unique position on the Bosphorus Strait, which connects the Black Sea to the Sea of Marmara and the Mediterranean, has resulted in the city being a jealously guarded centre of world trade since the Byzantine era.

Protected by water on three sides, with the natural harbour of the Golden Horn nestled within the city, Istanbul has always enjoyed an ideal location for conducting east-west trade and building empires. The city fell to the Ottomans in 1453 but remained a vital trading post for spices and textiles brought to Europe via the Silk Road from as far away as China.

Because of its prime geographic position, Istanbul has suffered from frequent sieges over the centuries. That which started out as a Hellenic outpost to New Rome, the world's first Christian capital, went on to become the headquarters of the Ottoman Sultans, masters of the world's biggest Muslim Empire. Its identity today is altogether more secular but still combines both eastern and European characteristics.

As a result of such a rich and varied history, Istanbul's architectural inheritance is second to none. Fine examples are visible throughout the city with stunning Ottoman mosques, classical columns, Byzantine structures, ancient city walls and fine Orthodox churches.

In recent years, rapid industrialisation has drawn thousands of rural poor to the metropolis, resulting in a vast social gap between ‘natives' and migrants and a very high growth rate. However, with Turkey's economy making an upturn in recent years and future EU membership firmly on the cards, Istanbul is currently thriving - for the wealthy at least. The city has become increasingly cosmopolitan of late: the arts and music scene is flourishing, and new bars, clubs, private art galleries, restaurants and designer fashion outlets are opening all the time.

Istanbul's climate is, in the main, a Mediterranean one, although it is affected by climatic variations due to its location on the Marmara Sea and Bosphorus. Summers are hot and winters cold, with spring and autumn usually sunny and warm although they can be changeable. Light snow is common in the winter.