Map of the mouth of the Mediterranean. Surely, Tarifa is the southernmost protrusion of the European continent into the Gibraltar Strait. So, this begs the question: why is this area known by the name of an inconsequential piece of rock a few miles to the northeast? What historical ocurrence made the Rock of Gibraltar so significant that it is the identifier of the mouth of the Mediterranean?
Gibraltar looks like this:
http://upload.wikimedia.org/wikipedia/commons/8/8b/Rock_of_Gibraltar_northwest.jpg
Tarifa looks like this:
http://webehigh.org/wp-content/uploads/2013/03/tarifa.jpg
As you can see, Tarifa is flat land, low and not rising high above sea level. Gibraltar is a great rock, rising 387 meters, 1,270 ft above the sea.
From the deck of a ship, on a clear day you can probably see Talifa when you are about 12 miles away. You can see Gibraltar from more than 50 miles.
It is the fact that Gibraltar is such a prominent and visible landmark that makes it one of the "Pillars of Hercules", and traditionally the gate between the Mediterranean and the Atlantic.
Can you glean any clues from the geography? So Tarifa is a little farther south, but the Bay of Gibraltar provides the better port. Historically, Gibraltar has been an important naval base for the British and the Rock of Gibraltar makes it an even more interesting tourist attraction.
Tarifa may be a bit further south, but it lacks a good natural harbor. Only a small fishing harbor and coast guard base exists today at Tarifa, and that is only possible because of the construction of a breakwater in the mid-20th century. So, historically, Gibralter was the furthest-south point with a good harbor, which made it strategic for controlling access to the Mediterranean Sea.
