A look at the map reveals, for instance, why Turkey is often called a peninsula. It is surrounded on three sides by water, though the water on its northwestern side (the Sea of Marmara) is scarcely comparable with that to the north (the Black Sea), the south (the Mediterranean), or the southwest (the Aegean Sea). The Sea of Marmara is connected to the Black Sea by the Bosphorus Straits and to the Aegean Sea by the Dardenelles. For as long as anyone cares to remember struggle for control of these two passageways has dictated the course of history, from the Trojan war, when the Greeks took control of the Dardanelles from Troy, to the military and diplomatic struggles, then and now, in and around ancient Byzantium (now Istanbul) for mastery of the Bosphorus.
Another glance at the map shows that a small part of Turkey is northwest of the Sea of Marmara while the vast stretches of this huge country lies to the east -- in Asia. For there, at Istanbul, is the boundary between two continents, Europe and Asia. These are continents, in the physical sense, in somewhat the same sense that Anatolia, the Asian part of Turkey, is a peninsula, i.e., by definition. Europe and Asia are one land mass and thus properly a single continent. But in social, political, and religious senses their separate identity is a powerful reality.
To go from Greece to Turkey is to go from a society in which Orthodox Christianity is deeply ingrained to one dominated by Islam, from a culture that is fed by the philosophical traditions of Plato and Aristotle and the ancient relgions of Zeus and Apollo to a culture that reaches back to the empire of the Hitittes and beyond, and, more recently, to the centuries-long Ottoman rule. By crossing the Bosphorus the traveller also sets foot on the path taken by adventurers such as Marco Polo and the tradesmen who followed him on the Silk Road to and from China -- and the route taken by more than one conqueror, the most famous of which is Alexander the Great.
Turkey is Asia; Greece is Europe. Even mono-cultural Americans can feel the difference.
The Footsteps of Paul tour travelled from Europe to Asia. Paul went the other way (actually, to be picky about it, he went both ways) but there is no record that he ever set foot in the parts of Turkey, Istanbul and Cappadocia, visited by the tour. (Ephesus, where Paul didgo, was included in the tour's "Greek" portion and is treated elsewhere.) Those who are interested in a slight detour may spend a moment with a short discussion of Paul in Anatolia.
Otherwise, carry on .... To Istanbul