Gulf of Tadjoura in the context of "Bab-el-Mandeb"

The Gulf of Aden (Arabic: خليج عدن; Somali: Gacanka Cadmeed) is a deepwater gulf of the Indian Ocean between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Channel, the Socotra Archipelago, Puntland in Somalia and Somaliland to the south. In the northwest, it connects with the Red Sea through the Bab-el-Mandeb strait, and it connects with the Arabian Sea to the east. To the west, it narrows into the Gulf of Tadjoura in Djibouti. The Aden Ridge lies along the middle of the gulf, and tectonic activity at the ridge is causing the gulf to widen by about 15 mm (0.59 in) per year.

The ancient Greeks regarded the gulf as one of the most important parts of the "Erythraean Sea". It later came to be dominated by Muslims, as the area around the gulf converted to Islam. From the late 1960s onwards, there was an increased Soviet naval presence in the Gulf. The importance of the Gulf of Aden declined while the Suez Canal was closed, but it was revitalized when the canal was reopened in 1975, after being deepened and widened by the Egyptian government.

The Aden Ridge is a part of an active oblique rift system located in the Gulf of Aden, between Somalia and the Arabian Peninsula to the north. The rift system marks the divergent boundary between the Somali and Arabian tectonic plates, extending from the Owen transform fault in the Arabian Sea to the Afar triple junction or Afar Plume beneath the Gulf of Tadjoura in Djibouti.

The Gulf of Aden is divided east to west into three distinct regions by large-scale discontinuities, the Socotra, Alula Fartak, and Shukra-El Sheik transform faults. Located in the central region, bounded by the Alula Fartak fault and Shukra-El Sheik fault, is the Aden spreading ridge. The Aden Ridge connects to the Sheba Ridge in the eastern region and to the Tadjoura Ridge in the western region. Due to oblique nature of the Aden Ridge, it is highly segmented. Along the ridge there are seven transform faults that offset it to the north.

Lake Assal (Arabic: بحيرة عسل Buḥayrah ʿAsal, lit. “Honey Lake”) is a crater lake in central-western Djibouti. It is located at the western end of Gulf of Tadjoura between Arta Region, and Tadjoura Region, touching Dikhil Region, at the top of the Great Rift Valley, some 120 km (75 mi) west of Djibouti city. Lake Assal is a saline lake that lies 155 m (509 ft) below sea level in the Afar Triangle, making it the lowest point on land in Africa and the third-lowest point on Earth after the Sea of Galilee and the Dead Sea. No outflow occurs from the lake, and due to high evaporation, the salinity level of its waters is 10 times that of the sea, making it the fifth most saline body of water in the world, behind Garabogazköl, Lake Retba, Gaet'ale Pond and Lake Elton. The salt in the lake is exploited under four concessions awarded in 2002 at the southeast end of the lake; the major share of production (nearly 80%) is held by Société d’Exploitation du Lac and Société d’Exploitation du Salt Investment S.A de Djibouti.

The lake is a protected zone under Djibouti's National Environmental Action Plan of 2000. However, the law does not define the boundary limits of the lake. Since the exploitation of the salt from the lake was uncontrolled, the Plan has emphasized the need for managing the exploitation to avoid negative impact on the lake environment. The Government of Djibouti has initiated a proposal with UNESCO to declare the Lake Assal zone and the Ardoukoba volcano as a World Heritage Site.

Djibouti (also called Djibouti City and Jibuti in early Western texts) is the capital city of the Republic of Djibouti. It is located in the coastal Djibouti Region on the Gulf of Tadjoura.

Djibouti has a population of around 780,000 inhabitants, which counts for 73% of the country's population. The settlement was founded in 1888 by the French, on land leased from the ruling Somali and Afar Sultans. During the ensuing period, it served as the capital of French Somaliland and its successor the French Territory of the Afars and Issas.

The Awash River (sometimes spelled Awaash; Oromo: Awaash or Hawaas, Amharic: ዐዋሽ, Afar: Hawaash We'ayot, Somali: Webiga Dir, Italian: Auasc) is a major river of Ethiopia. Its course is entirely contained within the boundaries of Ethiopia and empties into a chain of interconnected lakes that begins with Lake Gargori and ends with Lake Abbe (or Abhe Bad) on the border with Djibouti, about 100 kilometres (62 mi) from the head of the Gulf of Tadjoura. The Awash River is the principal stream of an endorheic drainage basin covering parts of the Amhara, Oromia and Somali Regions, as well as the southern half of the Afar Region. The Awash River basin, spanning 23 administrative zones, covers 10% of Ethiopia's area.

The basin usually has two rainy seasons, a shorter one around March (Belg), and a longer one between June and September (Kiremt), which partly fall into one longer rainy season. Climate change is predicted to increase the water deficiency in all seasons and for parts of the basin, due to a projected increase in temperature and decrease in precipitation.

The Tadjourah Region Somali: Gobolka Tajoora, Afar: Rakaakay Tagórri) is a region in north-central Djibouti, the largest of its six regions. With its capital at Tadjourah, it has an area of 7,100 square kilometres (2,700 sq mi). It lies along the Gulf of Tadjoura, and the coastal city of Tadjoura. The region has active salt and fisheries industries, and is served by the Tadjoura Airport. In total area, it is larger than Brunei and smaller than Cyprus.