Geography

The Rock of Gibraltar (sometimes called the Pillar of Hercules or by its Latin name, Calpe) is a monolithic limestone promontory located in Gibraltar, off the southwestern tip of Europe on the Iberian Peninsula. It is 426 metres (1,396 feet) high. The Rock is Crown property of the United Kingdom, and borders Spain. The sovereignty of Gibraltar was transferred to the United Kingdom of Great Britain by the Treaty of Utrecht in 1713 after the War of the Spanish Succession. Most of the Rock's upper area is covered by a nature reserve, which is home to around 250 Barbary Macaques, commonly known as 'apes'; they are the only wild monkeys found in Europe. These macaques, as well as a labyrinthine network of tunnels attracts a large number of tourists per year.

In ancient times, the Rock of Gibraltar was one of the Pillars of Hercules and was known to the Greeks as Mons Calpe, the other pillar being Mons Abyla on the African side of the Strait. The Rock of Gibraltar marked the limit to the known world and to pass beyond it was to sail to certain destruction over the bottomless waterfall at the edge of the world.

The territory covers 6.54 sq km 2.53 square miles). It shares a 1.2 km (0.75 mile land border with Spain and has 12 km (7.5 miles) of shoreline. There are two coasts (sides) of Gibraltar - the East Side, which contains the settlements of Sandy Bay and Catalan Bay, and the West Side, where the vast majority of the population lives.

Gibraltar is one of the most densely populated territories in the world, with approximately 4,290 people per square kilometre. The growing demand for space is being increasingly met by land reclamation, which comprises approximately one tenth of the territory's total area.

The Rock itself is made of limestone and is 1,396 feet (426 m) high. It contains many miles of tunnelled roads, most of which are operated by the military and hence closed to the public.

Geology

The Rock of Gibraltar is a monolithic limestone promontory created when the African tectonic plate collided tightly with Europe. The Mediterranean became a lake that, in the course of time, dried up during the Messinian salinity crisis. The Atlantic Ocean broke through the Strait of Gibraltar, and the resultant flooding created the Mediterranean Sea.

Today, the Rock of Gibraltar forms a peninsula jutting out into the Strait of Gibraltar from the southern coast of Spain. The Rock's highest point stands 426 metres (1396 feet) above the strait. Its east face forms a very impressive near-cliff, while its west slope is relatively gentle.

Calcite, the mineral which makes up limestone, dissolves slowly in rainwater. Over time, this process can form caves. Since the Rock of Gibraltar is made of limestone, it is not surprising that it contains a number of caves. St. Michael's Cave, located halfway up the western slope of the Rock, is a popular tourist attraction.

Gorham's Cave is located near sea level on the steep eastern face of the Rock. It is noteworthy because archaeological excavations in the cave have found evidence that Neanderthals used it as far back as 30,000 years ago. It is especially significant because plant and animal remains found in the cave (and others nearby) indicate that the Neanderthals had a highly varied diet.

Natural Resources

It has negligible natural resources and limited natural freshwater resources, until recently using large concrete or natural rock water catchments to collect rain water. It now has a desalination plant using reverse osmosis, built into the Rock itself.