It's hard to know where to start when you begin talking about sightseeing in Istanbul. A high ancient Roman wall may abut a glittering skyscraper, an ornate Ottoman mosque may stand only yards away from both a Greek Orthodox church and a synagogue, and a fantastically modern bridge may lead you to a narrow cobbled street filled with restored centuries-old houses. Do you start with ancient history and artifacts, or do you start with the Roman, Byzantine or Ottoman Empires? Istanbul was capital of all three. Few cities in the world have such an amazing array of treasures, from those made by man and collected or constructed by three of the world's preeminent empires, to those made by nature, like the beautiful Bosphorus, which divides the city in two, the Marmara Sea and the Golden Horn, and Istanbul's seven hills. This modern city's maze of narrow streets climbing steeply angled hills and affording fantastic views at every turn attest to the city's over 3,500 years of civilization.

In Istanbul, the glorious Haghia Sofia, a Holy Roman Church built under Justinian in the 6 century AD, stands opposite the equally impressive Blue Mosque, of nearly the same size and grandeur, but built almost 1,000 years later. Nearby Topkapi Palace gives you a glimpse at the lifestyles of the Ottoman sultans, who lived here for over 400 years, as well as housing fabulous collections of jewels and religious artifacts.

Other must-sees include the Dolmabahce Palace-one of the extravagant palaces built for sultans, the Basilica Cisterns, the fortress of Rumeli Hisari and Anadolu Hisari and the Grande Bazaar. And do not leave Istanbul without visiting a hamam, a traditional Turkish bath, and getting scrubbed and massaged as residents and visitors have for millennia. There's so much to do in Istanbul, and the city is so full of surprises at every turn, that it would be hard to be at a loss for things to do! There are plenty of reasons that most people who come to Istanbul once, always want to come back.