Istanbul, which is the only city in the world that spans two continents, is home to its meeting point between Asia and Europe – Bosphorus Strait. This meeting point is joined by the city’s iconic Bosphorus Bridge, also known as 15 July Martyrs Bridge. Bosphorus is also the world’s narrowest strait used for navigation; it connects the Black Sea with the Sea of Marmara. Its formation has been a topic of various debates, however Bosphorus has emerged as a popular place of tourist interest. Completed in 1973, the Bosphorus Bridge had the fourth longest suspension bridge span in the world then; and it remained the longest suspension bridge in Europe until the completion of the Humber Bridge in 1981. Bosphorus is now also used by ferries, fishing boats, cruises and yachts.