When you first see the Rock of Gibraltar, whether it is from the air, from the sea or from either the Costa del Sol or the western end of the Bay, it is its impressive stature, towering isolated above the surrounding countryside, that causes the greatest impact. It has had this effect on people for many thousands of years. Gibraltar is a beacon which signals the position of the Strait of Gibraltar, the narrow neck which separates Europe from Africa and provides the only link between the Atlantic Ocean and the Mediterranean Sea.
This beacon which attracted the early inhabitants had many advantages as a home. Being limestone, the Rock which is geologically very different from the surrounding landscape, is riddled with caves. Over 140 have been discovered so far. Those which had openings to the outside world made perfect shelters. The climate was also colder than today which meant that the sea level was lower: off the eastern cliffs of the Rock a large, flat, sandy plain stretched out towards the distant Mediterranean. It was full of good hunting. There were many rabbits, red deer, wild cattle and horse along with now extinct species of elephant and rhinoceros; on the cliffs there were ibexes, wild mountain goats. The scene was close to paradise for the early inhabitants of Gibraltar. The hunting was so good that it attracted other predators, especially hyaenas, leopards and lions. So these people must have forayed with caution.
So why is Gibraltar, a lump of limestone, so different from the surrounding countryside? It all has to do with events which took place long before any kind of human had appeared on the face of the earth. The first thing to remember is that limestone is made up of millions of small shelled animals which have died and settled in the sea bed; slowly these shells harden and become rock. So another point to remember is that when you walk on the Rock you are stepping on an ancient sea bed!
Imagine then, for millions of years, a mass of limestone is growing under the sea. This is happening around 200 million years ago. The continents look nothing like they do today. Dinosaurs roam the land. Slowly over millions of years the continents assume their present shape. As Africa barges into Europe, the land folds and forms mountain chains like the Alps. Other chunks are pushed out of their position. One piece is thrust westwards and comes to rest where Gibraltar is today. It is very different from the surrounding countryside which is made up of younger rocks.
For now it remains as a narrow peninsula stuck to the end of the Iberian Peninsula, linked to it by a narrow isthmus. This isthmus, covered by buildings and a runway, is sandy. You can still see this sand on the surface in places, often littered in marine shells from a more recent past when the sea separated Gibraltar from the rest. This would have last happened during the latest warm period of the glaciations, probably around 120 thousand years ago. Many still refer to Gibraltar as an island. Historically, biologically, even politically it has been an island even in recent times, but physically it is a peninsula.
For the person interested in natural history, whether it is on land or sea, Gibraltar is incredibly rich and full of surprises at any time of the year. It is a combination of geographical location, climate and a unique history, together with the preservation of areas of habitat, that has made it a tiny paradise for wildlife.