What city has a population of 14 million and is divided across two continents? [Hook] 

Istanbul, one of the most ancient cities in Europe, was once the capital of the Roman Empire, the Byzantine Empire, the Latin Empire, and the Ottoman Empire. [Characters] 

Believe me, that's a lot of history and makes for an intriguing story around every corner. [Essential Truth] 

It's time to go searching for your own history in this metropolis of cats, mosques, and Turkish coffee. [A Punchline]

What do you think? I'm not feeling to good about the punchline at the moment.