The Dardanelles (Turkish: Çanakkale Bogazi) is a narrow strait in northwestern Turkey connecting the Aegean Sea with the Marmara Sea.
Just like the Bosporus strait, it separates Europe (in this case the Gallipoli peninsula) and the mainland of Asia. The major city neighbouring the strait is Çanakkale (which takes its name from its famous castles; kale means "castle").
The strait has long had a strategic role in history (for example the Trojan War took place on the Asiatic side of the straits). The Persian army of Xerxes I and later the Macedonian army of Alexander the Great crossed the Dardanelles in opposite directions to invade each other's lands.
Having a vital importance for the Ottoman fleet for their domination over the eastern Mediterranean region, the strait was almost forced by the Allies during World War I with huge loss of life (see Anzac), almost ending the career of Winston Churchill (the Entente lost the battle on March 18, 1915).