What huge limestone mass lies on the southern coast of Spain?

The monolithic natural landmark jutting out from the southern tip of the Iberian Peninsula is known as Gibraltar, a British Overseas Territory. This impressive geological feature, often simply called "The Rock," is predominantly composed of Jurassic limestone, formed from the compacted shells of tiny sea creatures over 200 million years ago. Tectonic plate movements uplifted these layers, shaping the iconic promontory we see today. Its strategic location at the entrance to the Mediterranean Sea, guarding the narrow Strait of Gibraltar, has made it a highly contested and significant site throughout history.

Historically, the Romans referred to this landmark as one of the Pillars of Hercules, marking the western edge of the known world. Beyond its geological and historical importance, Gibraltar offers fascinating unique characteristics. It is home to Europe's only wild population of Barbary macaques, a species of tailless monkeys whose presence is steeped in local legend. The limestone composition has also led to the formation of numerous natural cave systems, such as St. Michael's Cave, which have been further expanded by an extensive network of man-made tunnels, originally for military defense. This blend of natural wonder and human history makes it a truly remarkable place.