istanbul is moving between the black sea and the mediterranean sea
the following is a list of notable black sea resort towns modern military use the 1936 montreux convention provides for free passage of civilian ships between the international waters of the black and the mediterranean seas
 in the 20th century the 1st and 2nd world wars as well as the suez crisis and the cold war led to a shift of trade routes to the european northern ports which changed again towards the southern ports through european integration the activation of the silk road and free world trade