Foreigners snap up Istanbul's iconic waterfront mansions They are among Istanbul's most iconic sights -- magnificent waterside mansions strung out along the Bosphorus as the waters of the strait dividing Europe and Asia lap almost at their front doors. Once the preserve of the Ottoman elite and affluent foreigners working in what was Constantinople, the mansions, known as yalis, were made famous in novels and more recently through modern Turkey's hugely successful TV soap operas. IMAGES AND SOUNDBITES