The Gibraltar Nature Reserve (formerly the Upper Rock Nature Reserve) is a protected nature reserve in the British Overseas Territory of Gibraltar that covers over 40% of the territory's land area. It was established as the Upper Rock Nature Reserve in 1993 under the International Union for Conservation of Nature's category Ia (strict nature reserve) and was last extended in 2013. It is known for its semi-wild population of Barbary macaques, and is an important resting point for migrating birds.

Originally named the Upper Rock Nature Reserve, it was limited to the upper part of the Rock of Gibraltar, a long and narrow limestone peninsula that rises to a height of 426 metres (1,398 ft) above sea level.^[1][2] The Rock is part of the Betic Cordillera, formed about 200 million years ago.^[3] From the crest of the rock there is a dramatic view of the area, including Spain across the Bay of Gibraltar and Jebel Musa of Morocco across the Strait of Gibraltar. It is an area of considerable natural beauty and one of the main tourist attractions in Gibraltar.^[1]

The Upper Rock area of the nature reserve can be reached by road or by the Gibraltar Cable Car, next to the Gibraltar Botanic Gardens.^[4]

The reserve was established in 1993^[2] to protect the area of land that the United Kingdom's Ministry of Defence had decommissioned from military use. Its purpose is to preserve the wildlife and natural and historical sites, while providing access to the public.^[5] The flora and fauna of the nature reserve are protected by the law of Gibraltar.^[6]

The nature reserve was last extended in 2013 when it was renamed the Gibraltar Nature Reserve to reflect its wider scope outside the Upper Rock. The protected area now covers the Great Gibraltar Sand Dune, Windmill Hill and the Europa Foreshore.^[2]

Gibraltar has a typical Mediterranean climate, moderated by the sea that almost surrounds the peninsula. Summers are warm and dry, while winters are cool and wet. Temperatures range from 13.4 °C to 24.2 °C (56.1 °F to 75.6 °F). Annual rainfall is about 768 millimetres (30.2 in).^[6] The Levanter clouds provide condensation that keeps the vegetation green even in the dry season.^[5] These clouds form when moisture-laden easterly winds are forced upward by the cliffs of Gibraltar, and often form a cap over the Rock.^[6]

The nature reserve contains many of Gibraltar's important natural history sites including caves such as St. Michael's Cave, with its many stalagmites and stalactites.^[1] St. Michael's Cave was first mentioned by Pomponius Mela in 45 AD, and many sources have mentioned it since. It has become an important tourist attraction. Concerts are held in its main chamber.^[7] Forbes' Quarry is where the Neanderthal discovery was made in 1848. The Gibraltar 1 skull was one of the first to be found.^[8] Neanderthal skulls have also been found at the Devil's Tower Cave on the North Front.^[9] It is possible that some of the last Neanderthals may have made the caves of Gibraltar their home before they died out 30,000 years ago.^[8]

The Gibraltar Heritage Trust manages conservation of the historical sites and their development as tourist attractions. These include the O'Hara's Battery, 100 Ton Gun at Napier of Magdala Battery, Heritage Centre at Princess Caroline's Battery and the Parson's Lodge Battery.^[5] Other military sites that are open to the public are the Moorish Castle, Devil's Gap Battery, Princess Anne's Battery, World War II Tunnels, Great Siege Tunnels and Charles V Wall.

In the past, the Upper Rock was tree-covered. Most of the trees were felled for fuel during the Great Siege of Gibraltar between 1779 and 1783. Trees today mostly produce berries that are eaten by birds, who presumably dropped their seeds on the rock. The most common is the olive (Olea europea). Carob (Ceratonia siliqua) and nettle trees (Celtis) are also found. Trees have been planted along the paths, including the stone pine (Pinus pinea) and Aleppo pine (Pinus halepensis). Both are native to the region, but the Aleppo pine is particularly common in dry, limestone regions. There was a drought in the 1990s when many of the introduced trees died, although the Aleppo pine fared better than others.^[10]

Gibraltar has more than six hundred species of flowering plants.^[5] The maquis, or dense Mediterranean scrub, is mostly made up of tall bushes that include wild olive, Mediterranean buckthorn, lentisc, Osyris and terebinth, and smaller bushes that include shrubby scorpion vetch, spiny broom, teline, wild jasmine, shrubby germander and felty germander. The bay laurel and the dwarf fan palm are also found in parts of the maquis. Understory plants include the intermediate periwinkle, Butcher’s broom, Italian arum and Bear's breech. The firebreaks in the maquis are home to plants such as paper-white narcissus, common asphodel, giant Tangier fennel, wild gladiolus, Galactites and mallow bindweed.^[11]

There are small areas of garrigue in the reserve, low scrub that includes wild rosemary, esparto grass, white asparagus, toothed lavender, cut-leaved lavender, teline, Prasium, shrubby scorpion vetch and germanders.^[11] The many cliffs around the reserve harbor joint pine, dwarf fan palm, sweet alison, Biscutella and wild parsley.^[10] Distinctive plants include the Gibraltar candytuft, white Gibraltar chickweed, Gibraltar saxifrage and Gibraltar thyme. The Gibraltar campion is a very rare species found only on Gibraltar that was thought for a while to be extinct.^[12]

• Animals of Gibraltar on Wikimedia Commons

• Northern peak of the Rock of Gibraltar
• A Barbary macaque
• View of the African coast
• Top of the Charles V Wall