You’ll eventually run into the Bosphorus if you’re ever in Istanbul. One of history’s most important waterways, the narrow Bosphorus connects Istanbul to Russia via the Black Sea and to the Mediterranean via the Dardanelles strait. You can cruise this historic waterway for about $7-10US. When you reach the Bosphorus (and you will), look for a big plaza on the waterfront with throngs of people eating fish sandwiches and grilled corn. Pick up your cruise here. There’s no need for reservations in the off-season. Bring a jacket; it gets chilly on the water.